Solar Electricity Handbook 2011: A Simple Practical Guide to Solar Energy - Designing and Installing Photovoltaic Solar Electric Systems - Michael Boxwell (2011)
Appendix B. Solar Insolation
Solar insolation shows the daily amount of energy from the sun you can expect per square metre at your location, averaged out over the period of a month. The figures are presented as an average irradiance, measured in kilowatt-hours per square metre spread over the period of a day (kWh/m²/day).
Averages have been collated over a 22-year period between 1983 and 2005, based on a three-hour sample rate.
The book only shows solar insolation figures for the United States, Canada, Australia, New Zealand, UK and Ireland. Whilst I have tried to show this information as clearly as possible, the information is in tabular form which does not display well on some smaller eBook readers. More detailed information can be accessed at www.SolarElectricityHandbook.com, with figures for every major town and city in every country in the world, thereby allowing you to access information that is specific to your area.
Understanding this information
The amount of energy you capture from the sun differs, depending on the tilt of the solar panels. If you mount your solar panels horizontally or vertically, you will capture less energy than if you face them due south (due north in the Southern Hemisphere) and tilt them towards the sun.
The tables on the following pages show the irradiance figures based on mounting your solar panels at the following angles:
· Flat (horizontal)
· Upright
· Tilted towards the equator for best year-round performance
· Tilted for best performance during the winter months
· Tilted for best performance during the summer months
· Tilted with the angle adjusted each month throughout the year
Where the figures show the panels tilted at a fixed angle, I show this angle in the left hand column as the angle adjustment from an upright (vertical) position. On the bottom row, where the optimum tilt changes each month, I show this angle underneath each month’s irradiance figures. Please note: all angles are in degrees from vertical.
For a more detailed explanation of these figures, refer to the chapter on Calculating Solar Energy.
Solar insolation values - Australia
New South Wales
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
5.91 |
5.25 |
4.48 |
3.56 |
2.73 |
2.49 |
2.68 |
3.49 |
4.6 |
5.41 |
5.88 |
6.24 |
Upright - 0° |
2.34 |
2.56 |
2.93 |
3.36 |
3.43 |
3.77 |
3.78 |
3.83 |
3.54 |
2.83 |
2.40 |
2.31 |
56° angle Year-round tilt |
5.38 |
5.11 |
4.84 |
4.42 |
3.87 |
3.90 |
4.04 |
4.68 |
5.33 |
5.50 |
5.43 |
5.57 |
40° angle Best winter tilt |
4.74 |
4.66 |
4.62 |
4.45 |
4.07 |
4.20 |
4.32 |
4.82 |
5.22 |
5.11 |
4.82 |
4.85 |
72° angle Best summer tilt |
5.78 |
5.32 |
4.82 |
4.16 |
3.46 |
3.37 |
3.54 |
4.28 |
5.16 |
5.63 |
5.80 |
6.04 |
Tilt adjusted each month |
5.78 72° |
5.34 64° |
4.84 56° |
4.47 48° |
4.07 40° |
4.27 32° |
4.32 40° |
4.82 48° |
5.33 56° |
5.63 64° |
5.80 72° |
6.24 80° |
Northern Territory
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
5.83 |
5.18 |
5.07 |
4.81 |
4.35 |
4.24 |
4.47 |
5.07 |
5.98 |
6.59 |
6.5 |
6.27 |
Upright - 0° |
2.43 |
1.81 |
2.28 |
3.09 |
3.73 |
4.24 |
4.23 |
3.75 |
2.99 |
2.02 |
2.32 |
2.79 |
73° angle Year-round tilt |
5.85 |
5.04 |
5.13 |
5.15 |
4.94 |
4.99 |
5.20 |
5.62 |
6.23 |
6.48 |
6.48 |
6.36 |
57° angle Best winter tilt |
5.58 |
4.68 |
4.94 |
5.21 |
5.23 |
5.43 |
5.61 |
5.83 |
6.13 |
6.04 |
6.12 |
6.13 |
89° angle Best summer tilt |
5.84 |
5.18 |
5.08 |
4.84 |
4.40 |
4.29 |
4.52 |
5.12 |
6.00 |
6.59 |
6.51 |
6.28 |
Tilt adjusted each month |
5.84 89° |
5.18 81° |
5.13 73° |
5.22 65° |
5.23 57° |
5.56 50° |
5.61 57° |
5.83 65° |
6.23 73° |
6.60 81° |
6.51 89° |
6.37 96° |
Queensland
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
6.19 |
5.39 |
4.95 |
3.98 |
3.23 |
3.02 |
3.22 |
4.04 |
5.12 |
5.52 |
6.07 |
6.35 |
Upright - 0° |
2.09 |
2.28 |
2.81 |
3.22 |
3.41 |
3.75 |
3.76 |
3.85 |
3.39 |
2.49 |
2.13 |
2.04 |
62° angle Year-round tilt |
5.65 |
5.22 |
5.19 |
4.61 |
4.12 |
4.13 |
4.29 |
4.99 |
5.65 |
5.50 |
5.61 |
5.71 |
46° angle Best winter tilt |
4.98 |
4.78 |
4.96 |
4.63 |
4.32 |
4.44 |
4.57 |
5.15 |
5.54 |
5.11 |
4.99 |
4.98 |
78° angle Best summer tilt |
6.06 |
5.41 |
5.15 |
4.34 |
3.71 |
3.59 |
3.78 |
4.56 |
5.47 |
5.62 |
5.98 |
6.18 |
Tilt adjusted each month |
6.06 78° |
5.42 70° |
5.19 62° |
4.65 54° |
4.32 46° |
4.50 38° |
4.57 46° |
5.15 54° |
5.65 62° |
5.62 70° |
5.98 78° |
6.35 86° |
South Australia
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
6.81 |
6.18 |
4.91 |
3.75 |
2.71 |
2.29 |
2.53 |
3.21 |
4.32 |
5.34 |
6.29 |
6.67 |
Upright - 0° |
2.54 |
2.94 |
3.32 |
3.72 |
3.54 |
3.48 |
3.63 |
3.52 |
3.37 |
2.87 |
2.54 |
2.42 |
55° angle Year-round tilt |
6.15 |
6.05 |
5.42 |
4.80 |
3.94 |
3.60 |
3.86 |
4.29 |
5.01 |
5.45 |
5.80 |
5.93 |
39° angle Best winter tilt |
5.36 |
5.49 |
5.19 |
4.86 |
4.15 |
3.87 |
4.12 |
4.41 |
4.89 |
5.05 |
5.12 |
5.13 |
71° angle Best summer tilt |
6.65 |
6.31 |
5.37 |
4.49 |
3.51 |
3.13 |
3.39 |
3.95 |
4.86 |
5.58 |
6.21 |
6.45 |
Tilt adjusted each month |
6.65 71° |
6.32 63° |
5.42 55° |
4.87 47° |
4.15 39° |
3.93 32° |
4.12 39° |
4.41 47° |
5.01 55° |
5.58 63° |
6.21 71° |
6.68 78° |
Victoria
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
6.36 |
5.83 |
4.51 |
3.23 |
2.23 |
1.78 |
1.94 |
2.59 |
3.55 |
4.72 |
5.74 |
6.22 |
Upright - 0° |
2.62 |
3.00 |
3.24 |
3.35 |
3.02 |
2.77 |
2.81 |
2.89 |
2.85 |
2.72 |
2.56 |
2.49 |
52° angle Year-round tilt |
5.75 |
5.74 |
5.04 |
4.22 |
3.33 |
2.87 |
3.00 |
3.48 |
4.10 |
4.80 |
5.30 |
5.53 |
36° angle Best winter tilt |
5.02 |
5.20 |
4.81 |
4.25 |
3.48 |
3.06 |
3.17 |
3.55 |
3.98 |
4.43 |
4.69 |
4.79 |
68° angle Best summer tilt |
6.22 |
6.00 |
5.01 |
3.97 |
3.00 |
2.52 |
2.67 |
3.24 |
4.02 |
4.94 |
5.67 |
6.01 |
Tilt adjusted each month |
6.22 68° |
6.02 60° |
5.04 52° |
4.27 44° |
3.48 36° |
3.09 28° |
3.17 36° |
3.55 44° |
4.10 52° |
4.94 60° |
5.67 68° |
6.23 76° |
Western Australia
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
8.41 |
7.49 |
5.93 |
4.34 |
3.09 |
2.62 |
2.82 |
3.62 |
5.04 |
6.41 |
7.71 |
8.45 |
Upright - 0° |
2.46 |
3.08 |
3.76 |
4.12 |
3.77 |
3.68 |
3.71 |
3.74 |
3.74 |
3.09 |
2.55 |
2.3 |
58° angle Year-round tilt |
7.51 |
7.31 |
6.53 |
5.46 |
4.29 |
3.89 |
4.05 |
4.69 |
5.80 |
6.54 |
7.06 |
7.39 |
42° angle Best winter tilt |
6.47 |
6.61 |
6.28 |
5.55 |
4.53 |
4.18 |
4.32 |
4.83 |
5.69 |
6.07 |
6.16 |
6.28 |
74° angle Best summer tilt |
8.18 |
7.62 |
6.43 |
5.07 |
3.82 |
3.37 |
3.56 |
4.3 |
5.59 |
6.67 |
7.59 |
8.14 |
Tilt adjusted each month |
8.18 74° |
7.63 66° |
6.53 58° |
5.56 50° |
4.53 42° |
4.25 34° |
4.32 42° |
4.83 50° |
5.80 58° |
6.67 66° |
7.59 74° |
8.45 82° |
Solar insolation values - Canada
Alberta
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.79 |
1.70 |
3.15 |
4.56 |
5.32 |
5.66 |
5.56 |
4.76 |
3.14 |
1.85 |
0.99 |
0.48 |
Upright - 0° |
1.58 |
2.60 |
3.52 |
3.63 |
3.24 |
3.11 |
3.19 |
3.36 |
3.03 |
2.51 |
1.81 |
0.95 |
36° angle Year-round tilt |
1.61 |
2.84 |
4.26 |
5.00 |
4.87 |
4.82 |
4.89 |
4.84 |
3.86 |
2.84 |
1.89 |
0.97 |
20° angle Best winter tilt |
1.66 |
2.85 |
4.09 |
4.55 |
4.30 |
4.21 |
4.30 |
4.33 |
3.63 |
2.80 |
1.93 |
1.00 |
52° angle Best summer tilt |
1.47 |
2.69 |
4.21 |
5.20 |
5.29 |
5.33 |
5.39 |
5.14 |
3.90 |
2.74 |
1.75 |
0.89 |
Tilt adjusted each month |
1.66 20° |
2.86 28° |
4.26 36° |
5.21 44° |
5.29 52° |
5.72 60° |
5.39 52° |
5.20 44° |
3.86 36° |
2.85 28° |
1.93 20° |
1.00 12° |
British Columbia
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.00 |
1.88 |
2.9 |
4.18 |
5.18 |
5.7 |
6.11 |
5.37 |
4.00 |
2.19 |
1.18 |
0.84 |
Upright - 0° |
1.52 |
2.44 |
2.73 |
2.93 |
2.89 |
2.86 |
3.15 |
3.43 |
3.54 |
2.62 |
1.73 |
1.37 |
42° angle Year-round tilt |
1.63 |
2.78 |
3.52 |
4.34 |
4.75 |
4.92 |
5.42 |
5.40 |
4.78 |
3.09 |
1.87 |
1.43 |
26° angle Best winter tilt |
1.67 |
2.78 |
3.37 |
3.97 |
4.17 |
4.24 |
4.69 |
4.85 |
4.53 |
3.06 |
1.91 |
1.48 |
58° angle Best summer tilt |
1.51 |
2.63 |
3.50 |
4.52 |
5.12 |
5.42 |
5.91 |
5.70 |
4.79 |
2.96 |
1.74 |
1.31 |
Tilt adjusted each month |
1.67 26° |
2.80 34° |
3.52 42° |
4.53 50° |
5.12 58° |
5.75 66° |
5.91 58° |
5.74 50° |
4.78 42° |
3.10 34° |
1.91 26° |
1.48 18° |
Manitoba
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.24 |
2.17 |
3.43 |
4.74 |
5.57 |
5.84 |
5.92 |
5.00 |
3.45 |
2.25 |
1.42 |
0.99 |
Upright - 0° |
2.15 |
3.01 |
3.50 |
3.48 |
3.16 |
3.00 |
3.15 |
3.28 |
3.07 |
2.81 |
2.34 |
1.84 |
40° angle Year-round tilt |
2.24 |
3.37 |
4.41 |
5.08 |
5.13 |
5.05 |
5.27 |
5.04 |
4.09 |
3.26 |
2.47 |
1.87 |
24° angle Best winter tilt |
2.31 |
3.39 |
4.24 |
4.65 |
4.51 |
4.42 |
4.57 |
4.53 |
3.87 |
3.24 |
2.54 |
1.95 |
56° angle Best summer tilt |
2.04 |
3.18 |
4.34 |
5.26 |
5.53 |
5.57 |
5.74 |
5.31 |
4.12 |
3.12 |
2.27 |
1.69 |
Tilt adjusted each month |
2.31 24° |
3.41 32° |
4.41 40° |
5.26 48° |
5.53 56° |
5.90 64° |
5.74 56° |
5.36 48° |
4.09 40° |
3.27 32° |
2.54 24° |
1.95 16° |
New Brunswick
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.61 |
2.46 |
3.68 |
4.46 |
4.91 |
5.45 |
5.25 |
4.78 |
3.75 |
2.45 |
1.53 |
1.28 |
Upright - 0° |
2.53 |
3.11 |
3.45 |
3.03 |
2.64 |
2.64 |
2.66 |
2.90 |
3.10 |
2.81 |
2.19 |
2.06 |
45° angle Year-round tilt |
2.67 |
3.59 |
4.52 |
4.69 |
4.56 |
4.75 |
4.68 |
4.73 |
4.32 |
3.37 |
2.39 |
2.15 |
29° angle Best winter tilt |
2.77 |
3.61 |
4.37 |
4.30 |
4.03 |
4.11 |
4.09 |
4.27 |
4.1 |
3.35 |
2.45 |
2.24 |
61° angle Best summer tilt |
2.43 |
3.37 |
4.45 |
4.84 |
4.90 |
5.21 |
5.08 |
4.98 |
4.34 |
3.22 |
2.20 |
1.95 |
Tilt adjusted each month |
2.77 29° |
3.62 37° |
4.52 45° |
4.85 53° |
4.90 61° |
5.48 68° |
5.08 61° |
5.02 53° |
4.32 45° |
3.38 37° |
2.45 29° |
2.24 22° |
Newfoundland and Labrador
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.23 |
2.07 |
3.27 |
4.16 |
4.75 |
5.16 |
4.90 |
4.36 |
3.25 |
2.09 |
1.26 |
0.99 |
Upright - 0° |
1.91 |
2.68 |
3.12 |
2.87 |
2.64 |
2.62 |
2.59 |
2.73 |
2.72 |
2.43 |
1.83 |
1.63 |
43° angle Year-round tilt |
2.03 |
3.06 |
4.03 |
4.30 |
4.34 |
4.48 |
4.35 |
4.29 |
3.73 |
2.89 |
1.99 |
1.7 |
27° angle Best winter tilt |
2.09 |
3.07 |
3.88 |
3.94 |
3.83 |
3.88 |
3.80 |
3.87 |
3.53 |
2.86 |
2.03 |
1.77 |
59° angle Best summer tilt |
1.87 |
2.89 |
3.99 |
4.47 |
4.68 |
4.93 |
4.74 |
4.53 |
3.77 |
2.77 |
1.85 |
1.55 |
Tilt adjusted each month |
2.09 27° |
3.08 35° |
4.03 43° |
4.48 51° |
4.68 59° |
5.20 66° |
4.74 59° |
4.58 51° |
3.73 43° |
2.90 35° |
2.03 27° |
1.77 20° |
Nova Scotia
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.54 |
2.39 |
3.47 |
4.29 |
4.98 |
5.57 |
5.49 |
4.85 |
3.91 |
2.66 |
1.57 |
1.21 |
Upright - 0° |
2.85 |
3.27 |
3.34 |
2.84 |
2.59 |
2.59 |
2.66 |
2.87 |
3.28 |
3.23 |
2.49 |
2.25 |
45° angle Year-round tilt |
2.89 |
3.70 |
4.39 |
4.45 |
4.62 |
4.85 |
4.90 |
4.82 |
4.62 |
3.82 |
2.64 |
2.27 |
29° angle Best winter tilt |
3.06 |
3.77 |
4.26 |
4.09 |
4.07 |
4.18 |
4.26 |
4.34 |
4.40 |
3.84 |
2.74 |
2.4 |
61° angle Best summer tilt |
2.56 |
3.42 |
4.28 |
4.61 |
4.96 |
5.31 |
5.32 |
5.06 |
4.60 |
3.60 |
2.39 |
2.01 |
Tilt adjusted each month |
3.06 29° |
3.78 37° |
4.39 45° |
4.61 53° |
4.96 61° |
5.60 68° |
5.32 61° |
5.10 53° |
4.62 45° |
3.86 37° |
2.74 29° |
2.42 22° |
Ontario
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.53 |
2.35 |
3.29 |
4.35 |
5.12 |
5.88 |
5.87 |
5.02 |
3.92 |
2.64 |
1.55 |
1.24 |
Upright - 0° |
2.63 |
3.04 |
3.02 |
2.83 |
2.61 |
2.64 |
2.74 |
2.91 |
3.21 |
3.07 |
2.29 |
2.21 |
46° angle Year-round tilt |
2.71 |
3.50 |
4.04 |
4.50 |
4.75 |
5.12 |
5.24 |
4.98 |
4.58 |
3.68 |
2.47 |
2.24 |
30° angle Best winter tilt |
2.85 |
3.55 |
3.91 |
4.13 |
4.19 |
4.41 |
4.55 |
4.49 |
4.36 |
3.69 |
2.56 |
2.37 |
62° angle Best summer tilt |
2.41 |
3.25 |
3.96 |
4.65 |
5.10 |
5.6 |
5.69 |
5.23 |
4.56 |
3.48 |
2.25 |
1.99 |
Tilt adjusted each month |
2.85 30° |
3.56 38° |
4.04 46° |
4.66 54° |
5.10 62° |
5.90 70° |
5.69 62° |
5.27 54° |
4.58 46° |
3.71 38° |
2.56 30° |
2.39 22° |
Prince Edward Island
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.35 |
2.10 |
3.22 |
4.28 |
5.40 |
6.05 |
6.04 |
5.22 |
3.91 |
2.34 |
1.29 |
0.98 |
Upright - 0° |
2.09 |
2.63 |
2.98 |
2.9 |
2.89 |
2.88 |
3.00 |
3.20 |
3.30 |
2.70 |
1.81 |
1.51 |
44° angle Year-round tilt |
2.21 |
3.04 |
3.90 |
4.42 |
5.01 |
5.23 |
5.37 |
5.20 |
4.57 |
3.23 |
1.98 |
1.6 |
28° angle Best winter tilt |
2.29 |
3.05 |
3.75 |
4.05 |
4.40 |
4.50 |
4.65 |
4.68 |
4.33 |
3.20 |
2.02 |
1.65 |
60° angle Best summer tilt |
2.03 |
2.87 |
3.87 |
4.59 |
5.40 |
5.75 |
5.85 |
5.48 |
4.58 |
3.09 |
1.84 |
1.47 |
Tilt adjusted each month |
2.29 28° |
3.06 36° |
3.90 44° |
4.60 52° |
5.40 60° |
6.09 68° |
5.85 60° |
5.52 52° |
4.57 44° |
3.24 36° |
2.02 28° |
1.65 20° |
Quebec
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.51 |
2.44 |
3.60 |
4.51 |
4.97 |
5.48 |
5.21 |
4.70 |
3.49 |
2.15 |
1.40 |
1.18 |
Upright - 0° |
2.42 |
3.16 |
3.44 |
3.10 |
2.71 |
2.7 |
2.69 |
2.91 |
2.91 |
2.47 |
2.03 |
1.97 |
43° angle Year-round tilt |
2.55 |
3.61 |
4.46 |
4.7 |
4.59 |
4.76 |
4.64 |
4.66 |
4.02 |
2.95 |
2.21 |
2.04 |
27° angle Best winter tilt |
2.64 |
3.64 |
4.31 |
4.31 |
4.05 |
4.12 |
4.05 |
4.20 |
3.81 |
2.93 |
2.26 |
2.12 |
59° angle Best summer tilt |
2.33 |
3.40 |
4.40 |
4.87 |
4.93 |
5.23 |
5.04 |
4.91 |
4.04 |
2.83 |
2.04 |
1.85 |
Tilt adjusted each month |
2.64 27° |
3.65 35° |
4.46 43° |
4.88 51° |
4.93 59° |
5.52 66° |
5.04 59° |
4.95 51° |
4.02 43° |
2.96 35° |
2.26 27° |
2.13 20° |
Saskatchewan
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.11 |
1.98 |
3.25 |
4.79 |
5.60 |
5.78 |
6.23 |
5.06 |
3.65 |
2.28 |
1.36 |
0.91 |
Upright - 0° |
1.94 |
2.77 |
3.32 |
3.57 |
3.21 |
3.00 |
3.33 |
3.36 |
3.33 |
2.90 |
2.30 |
1.74 |
40° angle Year-round tilt |
2.02 |
3.10 |
4.16 |
5.15 |
5.15 |
4.99 |
5.54 |
5.11 |
4.40 |
3.36 |
2.41 |
1.76 |
24° angle Best winter tilt |
2.08 |
3.11 |
4.00 |
4.71 |
4.51 |
4.36 |
4.78 |
4.58 |
4.16 |
3.33 |
2.48 |
1.83 |
56° angle Best summer tilt |
1.85 |
2.92 |
4.11 |
5.34 |
5.56 |
5.51 |
6.04 |
5.39 |
4.42 |
3.21 |
2.22 |
1.59 |
Tilt adjusted each month |
2.08 24° |
3.12 32° |
4.16 40° |
5.35 48° |
5.56 56° |
5.85 64° |
6.04 56° |
5.44 48° |
4.44 40° |
3.37 32° |
2.48 24° |
1.84 16° |
Solar insolation values - Ireland
Borders Region
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.57 |
1.25 |
2.34 |
3.96 |
5.34 |
5.41 |
4.92 |
4.10 |
2.87 |
1.53 |
0.71 |
0.4 |
Upright - 0° |
1.06 |
1.85 |
2.44 |
3.13 |
3.31 |
3.04 |
2.89 |
2.90 |
2.77 |
2.05 |
1.23 |
0.81 |
35° angle Year-round tilt |
1.10 |
2.03 |
2.98 |
4.25 |
4.89 |
4.61 |
4.31 |
4.10 |
3.50 |
2.32 |
1.29 |
0.82 |
19° angle Best winter tilt |
1.12 |
2.02 |
2.83 |
3.87 |
4.33 |
4.03 |
3.79 |
3.66 |
3.29 |
2.28 |
1.31 |
0.84 |
51° angle Best summer tilt |
1.01 |
1.94 |
2.98 |
4.44 |
5.32 |
5.09 |
4.75 |
4.36 |
3.55 |
2.25 |
1.21 |
0.75 |
Tilt adjusted each month |
1.12 19° |
2.04 27° |
2.98 35° |
4.46 43° |
5.32 51° |
5.47 58° |
4.75 51° |
4.43 43° |
3.50 35° |
2.32 27° |
1.31 19° |
0.84 12° |
Dublin, The Midlands and Midlands-East Regions
Flat - 90° |
0.62 |
1.19 |
2.09 |
3.34 |
4.32 |
4.36 |
4.21 |
3.52 |
2.53 |
1.44 |
0.82 |
0.5 |
Upright - 0° |
1.03 |
1.59 |
1.97 |
2.45 |
2.61 |
2.46 |
2.44 |
2.37 |
2.25 |
1.78 |
1.33 |
0.92 |
37° angle Year-round tilt |
1.08 |
1.78 |
2.48 |
3.42 |
3.90 |
3.76 |
3.70 |
3.42 |
2.93 |
2.05 |
1.41 |
0.94 |
21° angle Best winter tilt |
1.10 |
1.77 |
2.34 |
3.10 |
3.47 |
3.3 |
3.26 |
3.06 |
2.74 |
2.01 |
1.43 |
0.97 |
53° angle Best summer tilt |
1.01 |
1.71 |
2.50 |
3.59 |
4.25 |
4.14 |
4.05 |
3.64 |
2.98 |
1.99 |
1.32 |
0.87 |
Tilt adjusted each month |
1.10 21° |
1.79 29° |
2.48 37° |
3.62 45° |
4.25 53° |
4.42 60° |
4.05 53° |
3.71 45° |
2.93 37° |
2.05 29° |
1.43 21° |
0.97 14° |
South-East, West and South West Regions
Flat - 90° |
0.67 |
1.26 |
2.15 |
3.46 |
4.46 |
4.53 |
4.41 |
3.72 |
2.66 |
1.52 |
0.87 |
0.56 |
Upright - 0° |
1.06 |
1.65 |
2.00 |
2.52 |
2.66 |
2.51 |
2.52 |
2.48 |
2.35 |
1.86 |
1.37 |
0.99 |
38° angle Year-round tilt |
1.13 |
1.86 |
2.53 |
3.54 |
4.04 |
3.90 |
3.88 |
3.63 |
3.08 |
2.16 |
1.47 |
1.02 |
22° angle Best winter tilt |
1.15 |
1.84 |
2.40 |
3.22 |
3.59 |
3.43 |
3.43 |
3.25 |
2.88 |
2.12 |
1.49 |
1.05 |
54° angle Best summer tilt |
1.05 |
1.79 |
2.55 |
3.72 |
4.39 |
4.30 |
4.25 |
3.86 |
3.13 |
2.10 |
1.37 |
0.94 |
Tilt adjusted each month |
1.15 22° |
1.87 30° |
2.53 38° |
3.74 46° |
4.39 54° |
4.58 62° |
4.25 54° |
3.92 46° |
3.08 38° |
2.16 30° |
1.49 22° |
1.05 14° |
Solar insolation values - New Zealand
North Island
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
6.41 |
5.65 |
4.59 |
3.31 |
2.35 |
1.96 |
2.18 |
2.83 |
3.96 |
4.82 |
5.86 |
6.26 |
Upright - 0° |
2.58 |
2.87 |
3.23 |
3.36 |
3.14 |
3.05 |
3.20 |
3.17 |
3.20 |
2.73 |
2.55 |
2.46 |
53° angle Year-round tilt |
5.80 |
5.54 |
5.10 |
4.27 |
3.47 |
3.14 |
3.39 |
3.82 |
4.63 |
4.92 |
5.41 |
5.57 |
37° angle Best winter tilt |
5.07 |
5.03 |
4.87 |
4.3 |
3.64 |
3.36 |
3.60 |
3.91 |
4.52 |
4.56 |
4.79 |
4.83 |
69° angle Best summer tilt |
6.27 |
5.79 |
5.06 |
4.02 |
3.12 |
2.75 |
2.99 |
3.53 |
4.51 |
5.05 |
5.79 |
6.06 |
Tilt adjusted each month |
6.27 69° |
5.81 61° |
5.10 53° |
4.32 45° |
3.64 37° |
3.41 30° |
3.60 37° |
3.91 45° |
4.63 53° |
5.05 61° |
5.79 69° |
6.27 76° |
South Island
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
5.75 |
5.01 |
3.92 |
2.67 |
1.82 |
1.36 |
1.60 |
2.28 |
3.39 |
4.50 |
5.49 |
5.82 |
Upright - 0° |
2.75 |
2.94 |
3.18 |
3.14 |
3.05 |
2.64 |
3.01 |
3.08 |
3.17 |
2.90 |
2.76 |
2.67 |
46° angle Year-round tilt |
5.21 |
4.98 |
4.56 |
3.77 |
3.19 |
2.63 |
3.03 |
3.49 |
4.23 |
4.66 |
5.09 |
5.07 |
30° angle Best winter tilt |
4.54 |
4.50 |
4.34 |
3.78 |
3.35 |
2.81 |
3.23 |
3.57 |
4.10 |
4.28 |
4.47 |
4.39 |
62° angle Best summer tilt |
5.64 |
5.23 |
4.55 |
3.56 |
2.85 |
2.30 |
2.67 |
3.23 |
4.13 |
4.82 |
5.47 |
5.55 |
Tilt adjusted each month |
5.64 62° |
5.26 54° |
4.56 46° |
3.80 38° |
3.35 30° |
2.84 22° |
3.23 30° |
3.57 38° |
4.23 46° |
4.82 54° |
5.47 62° |
5.84 70° |
Solar insolation values - United Kingdom
London
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.75 |
1.37 |
2.31 |
3.57 |
4.59 |
4.86 |
4.82 |
4.20 |
2.81 |
1.69 |
0.92 |
0.60 |
Upright - 0° |
1.20 |
1.80 |
2.18 |
2.58 |
2.7 |
2.64 |
2.71 |
2.80 |
2.47 |
2.07 |
1.43 |
1.01 |
38° angle Year-round tilt |
1.27 |
2.04 |
2.76 |
3.67 |
4.17 |
4.2 |
4.25 |
4.16 |
3.26 |
2.41 |
1.53 |
1.05 |
22° angle Best winter tilt |
1.30 |
2.03 |
2.62 |
3.34 |
3.66 |
3.69 |
3.76 |
3.73 |
3.06 |
2.37 |
1.56 |
1.08 |
54° angle Best summer tilt |
1.19 |
1.95 |
2.77 |
3.84 |
4.52 |
4.63 |
4.66 |
4.41 |
3.31 |
2.33 |
1.43 |
0.97 |
Tilt adjusted each month |
1.30 22° |
2.05 30° |
2.76 38° |
3.86 46° |
4.52 54° |
4.91 62° |
4.66 54° |
4.46 46° |
3.26 38° |
2.41 30° |
1.56 22° |
1.08 14° |
South East
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.80 |
1.44 |
2.42 |
3.70 |
4.73 |
4.99 |
5.00 |
4.31 |
2.88 |
1.75 |
0.95 |
0.62 |
Upright - 0° |
1.34 |
1.94 |
2.33 |
2.71 |
2.8 |
2.72 |
2.81 |
2.9 |
2.57 |
2.18 |
1.51 |
1.09 |
38° angle Year-round tilt |
1.41 |
2.18 |
2.94 |
3.84 |
4.31 |
4.32 |
4.42 |
4.3 |
3.37 |
2.53 |
1.61 |
1.12 |
22° angle Best winter tilt |
1.44 |
2.18 |
2.81 |
3.5 |
3.79 |
3.80 |
3.92 |
3.86 |
3.17 |
2.49 |
1.64 |
1.16 |
54° angle Best summer tilt |
1.30 |
2.08 |
2.94 |
4.01 |
4.68 |
4.76 |
4.85 |
4.55 |
3.41 |
2.43 |
1.50 |
1.03 |
Tilt adjusted each month |
1.44 22° |
2.20 30° |
2.94 38° |
4.03 46° |
4.68 54° |
5.05 62° |
4.85 54° |
4.60 46° |
3.37 38° |
2.53 30° |
1.64 22° |
1.16 14° |
South West
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.81 |
1.51 |
2.49 |
3.91 |
5.13 |
5.37 |
5.28 |
4.37 |
3.07 |
1.74 |
1.01 |
0.65 |
Upright - 0° |
1.26 |
1.98 |
2.36 |
2.83 |
2.97 |
2.84 |
2.9 |
2.88 |
2.72 |
2.09 |
1.54 |
1.08 |
39° angle Year-round tilt |
1.34 |
2.25 |
3.00 |
4.07 |
4.7 |
4.64 |
4.68 |
4.34 |
3.60 |
2.45 |
1.65 |
1.13 |
23° angle Best winter tilt |
1.37 |
2.24 |
2.86 |
3.72 |
4.13 |
4.08 |
4.07 |
3.90 |
3.40 |
2.41 |
1.68 |
1.16 |
55° angle Best summer tilt |
1.25 |
2.14 |
3.00 |
4.24 |
5.08 |
5.12 |
5.12 |
4.59 |
3.64 |
2.36 |
1.54 |
1.04 |
Tilt adjusted each month |
1.37 23° |
2.26 31° |
3.00 39° |
4.26 47° |
5.08 55° |
5.43 62° |
5.12 55° |
4.65 47° |
3.60 39° |
2.45 31° |
1.68 23° |
1.16 16° |
East of England
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.72 |
1.34 |
2.37 |
3.60 |
4.68 |
4.90 |
4.86 |
4.20 |
2.82 |
1.64 |
0.91 |
0.57 |
Upright - 0° |
1.18 |
1.80 |
2.30 |
2.63 |
2.78 |
2.68 |
2.75 |
2.83 |
2.52 |
2.04 |
1.45 |
1.01 |
38° angle Year-round tilt |
1.25 |
2.03 |
2.89 |
3.71 |
4.24 |
4.21 |
4.27 |
4.16 |
3.30 |
2.36 |
1.55 |
1.04 |
22° angle Best winter tilt |
1.27 |
2.02 |
2.74 |
3.38 |
3.77 |
3.69 |
3.77 |
3.73 |
3.10 |
2.32 |
1.57 |
1.07 |
54° angle Best summer tilt |
1.16 |
1.94 |
2.90 |
3.89 |
4.61 |
4.65 |
4.69 |
4.41 |
3.35 |
2.29 |
1.45 |
0.96 |
Tilt adjusted each month |
1.27 22° |
2.04 30° |
2.89 38° |
3.91 46° |
4.61 54° |
4.96 62° |
4.69 54° |
4.48 46° |
3.30 38° |
2.37 30° |
1.57 22° |
1.07 14° |
East Midlands
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.64 |
1.31 |
2.20 |
3.37 |
4.44 |
4.51 |
4.50 |
3.82 |
2.59 |
1.54 |
0.8 |
0.51 |
Upright - 0° |
1.07 |
1.80 |
2.11 |
2.47 |
2.67 |
2.53 |
2.59 |
2.59 |
2.31 |
1.93 |
1.27 |
0.94 |
37° angle Year-round tilt |
1.13 |
2.01 |
2.64 |
3.45 |
4.01 |
3.88 |
3.95 |
3.74 |
3.01 |
2.22 |
1.36 |
0.96 |
21° angle Best winter tilt |
1.15 |
2.00 |
2.51 |
3.13 |
3.56 |
3.40 |
3.48 |
3.35 |
2.81 |
2.18 |
1.37 |
0.99 |
53° angle Best summer tilt |
1.05 |
1.92 |
2.66 |
3.62 |
4.37 |
4.28 |
4.33 |
3.98 |
3.06 |
2.15 |
1.27 |
0.89 |
Tilt adjusted each month |
1.15 21° |
2.02 29° |
2.64 37° |
3.65 45° |
4.37 53° |
4.57 60° |
4.33 53° |
4.05 45° |
3.01 37° |
2.22 29° |
1.37 21° |
0.99 14° |
West Midlands
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.71 |
1.35 |
2.28 |
3.47 |
4.51 |
4.69 |
4.69 |
4.04 |
2.70 |
1.65 |
0.90 |
0.57 |
Upright - 0° |
1.18 |
1.84 |
2.18 |
2.54 |
2.70 |
2.59 |
2.68 |
2.73 |
2.41 |
2.08 |
1.45 |
1.03 |
38° angle Year-round tilt |
1.24 |
2.06 |
2.74 |
3.56 |
4.09 |
4.05 |
4.14 |
3.99 |
3.14 |
2.4 |
1.55 |
1.06 |
22° angle Best winter tilt |
1.26 |
2.05 |
2.60 |
3.25 |
3.64 |
3.55 |
3.65 |
3.58 |
2.95 |
2.36 |
1.57 |
1.09 |
54° angle Best summer tilt |
1.15 |
1.97 |
2.75 |
3.73 |
4.45 |
4.46 |
4.53 |
4.23 |
3.19 |
2.31 |
1.44 |
0.97 |
Tilt adjusted each month |
1.26 22° |
2.07 30° |
2.74 38° |
3.76 46° |
4.45 54° |
4.74 62° |
4.53 54° |
4.30 46° |
3.14 38° |
2.40 30° |
1.57 22° |
1.09 14° |
North-East England
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.61 |
1.35 |
2.45 |
3.88 |
5.35 |
5.47 |
5.13 |
4.29 |
2.91 |
1.66 |
0.77 |
0.44 |
Upright - 0° |
1.17 |
2.03 |
2.61 |
3.04 |
3.31 |
3.06 |
3.01 |
3.05 |
2.81 |
2.27 |
1.38 |
0.94 |
35° angle Year-round tilt |
1.21 |
2.23 |
3.17 |
4.14 |
4.9 |
4.65 |
4.49 |
4.32 |
3.56 |
2.56 |
1.44 |
0.95 |
19° angle Best winter tilt |
1.24 |
2.22 |
3.03 |
3.76 |
4.33 |
4.07 |
3.95 |
3.85 |
3.34 |
2.52 |
1.46 |
0.98 |
51° angle Best summer tilt |
1.11 |
2.12 |
3.17 |
4.33 |
5.33 |
5.15 |
4.96 |
4.59 |
3.60 |
2.46 |
1.34 |
0.86 |
Tilt adjusted each month |
1.24 19° |
2.24 27° |
3.17 35° |
4.36 43° |
5.33 51° |
5.53 58° |
4.96 51° |
4.66 43° |
3.56 35° |
2.56 27° |
1.46 19° |
0.98 12° |
North-West England
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.66 |
1.32 |
2.30 |
3.63 |
4.92 |
5.00 |
4.88 |
3.98 |
2.73 |
1.53 |
0.79 |
0.50 |
Upright - 0° |
1.16 |
1.85 |
2.28 |
2.74 |
2.99 |
2.79 |
2.82 |
2.74 |
2.51 |
1.95 |
1.29 |
0.95 |
36° angle Year-round tilt |
1.21 |
2.06 |
2.83 |
3.79 |
4.49 |
4.31 |
4.31 |
3.94 |
3.23 |
2.23 |
1.37 |
0.96 |
20° angle Best winter tilt |
1.24 |
2.05 |
2.69 |
3.46 |
4.00 |
3.78 |
3.8 |
3.54 |
3.04 |
2.19 |
1.39 |
0.99 |
52° angle Best summer tilt |
1.12 |
1.96 |
2.83 |
3.97 |
4.89 |
4.77 |
4.73 |
4.18 |
3.28 |
2.16 |
1.28 |
0.88 |
Tilt adjusted each month |
1.24 20° |
2.07 28° |
2.83 36° |
3.99 44° |
4.89 52° |
5.08 60° |
4.73 52° |
4.25 44° |
3.23 36° |
2.23 28° |
1.39 20° |
1.00 12° |
Yorkshire and the Humber
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.62 |
1.30 |
2.30 |
3.51 |
4.69 |
4.78 |
4.64 |
3.89 |
2.67 |
1.54 |
0.75 |
0.47 |
Upright - 0° |
1.12 |
1.86 |
2.31 |
2.64 |
2.86 |
2.68 |
2.7 |
2.68 |
2.46 |
1.99 |
1.25 |
0.92 |
36° angle Year-round tilt |
1.16 |
2.06 |
2.85 |
3.64 |
4.24 |
4.09 |
4.07 |
3.83 |
3.16 |
2.28 |
1.32 |
0.94 |
20° angle Best winter tilt |
1.19 |
2.04 |
2.71 |
3.31 |
3.77 |
3.58 |
3.58 |
3.42 |
2.96 |
2.24 |
1.34 |
0.97 |
52° angle Best summer tilt |
1.08 |
1.96 |
2.86 |
3.82 |
4.63 |
4.50 |
4.47 |
4.08 |
3.21 |
2.2 |
1.24 |
0.86 |
Tilt adjusted each month |
1.19 20° |
2.06 28° |
2.85 36° |
3.85 44° |
4.63 52° |
4.83 60° |
4.47 52° |
4.15 44° |
3.16 36° |
2.28 28° |
1.34 20° |
0.97 12° |
Central and Southern Scotland
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.51 |
1.16 |
2.03 |
3.22 |
4.55 |
4.66 |
4.31 |
3.63 |
2.42 |
1.33 |
0.64 |
0.38 |
Upright - 0° |
0.99 |
1.75 |
2.05 |
2.46 |
2.85 |
2.68 |
2.58 |
2.55 |
2.28 |
1.76 |
1.14 |
0.86 |
34° angle Year-round tilt |
1.02 |
1.91 |
2.51 |
3.32 |
4.11 |
3.97 |
3.77 |
3.52 |
2.87 |
1.99 |
1.20 |
0.86 |
18° angle Best winter tilt |
1.04 |
1.90 |
2.37 |
3.00 |
3.64 |
3.47 |
3.31 |
3.17 |
2.68 |
1.95 |
1.21 |
0.89 |
50° angle Best summer tilt |
0.94 |
1.83 |
2.53 |
3.49 |
4.49 |
4.37 |
4.15 |
3.77 |
2.93 |
1.93 |
1.12 |
0.78 |
Tilt adjusted each month |
1.04 18° |
1.92 26° |
2.51 34° |
3.53 42° |
4.49 50° |
4.72 58° |
4.15 50° |
3.86 42° |
2.87 34° |
1.99 26° |
1.21 18° |
0.89 10° |
North Scotland
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.47 |
1.11 |
2.05 |
3.30 |
4.52 |
4.63 |
4.31 |
3.61 |
2.45 |
1.31 |
0.59 |
0.32 |
Upright - 0° |
0.99 |
1.74 |
2.16 |
2.59 |
2.88 |
2.7 |
2.61 |
2.57 |
2.38 |
1.80 |
1.12 |
0.77 |
33° angle Year-round tilt |
1.00 |
1.88 |
2.62 |
3.44 |
4.08 |
3.93 |
3.75 |
3.50 |
2.96 |
2.01 |
1.16 |
0.76 |
17° angle Best winter tilt |
1.03 |
1.87 |
2.46 |
3.12 |
3.62 |
3.43 |
3.30 |
3.15 |
2.77 |
1.97 |
1.18 |
0.79 |
49° angle Best summer tilt |
0.92 |
1.80 |
2.61 |
3.62 |
4.46 |
4.32 |
4.11 |
3.75 |
3.02 |
1.95 |
1.08 |
0.69 |
Tilt adjusted each month |
1.03 17° |
1.89 25° |
2.62 33° |
3.66 41° |
4.46 49° |
4.69 56° |
4.11 49° |
3.84 41° |
2.96 33° |
2.01 25° |
1.18 17° |
0.79 10° |
South Wales
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.72 |
1.33 |
2.21 |
3.52 |
4.57 |
4.75 |
4.71 |
3.97 |
2.71 |
1.55 |
0.89 |
0.59 |
Upright - 0° |
1.14 |
1.74 |
2.04 |
2.54 |
2.7 |
2.59 |
2.66 |
2.64 |
2.37 |
1.87 |
1.35 |
0.99 |
38° angle Year-round tilt |
1.21 |
1.97 |
2.59 |
3.61 |
4.15 |
4.11 |
4.16 |
3.91 |
3.12 |
2.18 |
1.45 |
1.03 |
22° angle Best winter tilt |
1.23 |
1.96 |
2.46 |
3.29 |
3.65 |
3.61 |
3.68 |
3.51 |
2.93 |
2.14 |
1.47 |
1.06 |
54° angle Best summer tilt |
1.13 |
1.89 |
2.61 |
3.78 |
4.51 |
4.52 |
4.56 |
4.14 |
3.17 |
2.11 |
1.36 |
0.95 |
Tilt adjusted each month |
1.23 22° |
1.98 30° |
2.59 38° |
3.80 46° |
4.51 54° |
4.80 62° |
4.56 54° |
4.20 46° |
3.12 38° |
2.18 30° |
1.47 22° |
1.06 14° |
North Wales
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.66 |
1.32 |
2.30 |
3.63 |
4.92 |
5.00 |
4.88 |
3.98 |
2.73 |
1.53 |
0.79 |
0.50 |
Upright - 0° |
1.14 |
1.83 |
2.26 |
2.72 |
2.97 |
2.77 |
2.81 |
2.72 |
2.49 |
1.93 |
1.27 |
0.92 |
37° angle Year-round tilt |
1.19 |
2.04 |
2.81 |
3.78 |
4.48 |
4.30 |
4.29 |
3.93 |
3.22 |
2.22 |
1.35 |
0.95 |
21° angle Best winter tilt |
1.22 |
2.03 |
2.68 |
3.44 |
3.98 |
3.77 |
3.79 |
3.52 |
3.02 |
2.18 |
1.37 |
0.98 |
53° angle Best summer tilt |
1.11 |
1.95 |
2.82 |
3.96 |
4.88 |
4.76 |
4.72 |
4.18 |
3.27 |
2.15 |
1.26 |
0.87 |
Tilt adjusted each month |
1.22 21° |
2.05 29° |
2.81 37° |
3.98 45° |
4.88 53° |
5.08 60° |
4.72 53° |
4.24 45° |
3.22 37° |
2.22 29° |
1.37 21° |
0.98 14° |
Northern Ireland
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.61 |
1.25 |
2.15 |
3.39 |
4.54 |
4.54 |
4.30 |
3.64 |
2.56 |
1.42 |
0.74 |
0.43 |
Upright - 0° |
1.09 |
1.79 |
2.12 |
2.55 |
2.79 |
2.58 |
2.54 |
2.51 |
2.36 |
1.82 |
1.25 |
0.82 |
35° angle Year-round tilt |
1.13 |
1.98 |
2.62 |
3.51 |
4.12 |
3.9 |
3.79 |
3.56 |
3.02 |
2.08 |
1.32 |
0.83 |
19° angle Best winter tilt |
1.16 |
1.97 |
2.49 |
3.19 |
3.66 |
3.42 |
3.34 |
3.19 |
2.83 |
2.04 |
1.34 |
0.86 |
51° angle Best summer tilt |
1.05 |
1.89 |
2.64 |
3.68 |
4.49 |
4.27 |
4.15 |
3.79 |
3.07 |
2.02 |
1.24 |
0.77 |
Tilt adjusted each month |
1.16 19° |
1.99 27° |
2.62 35° |
3.71 43° |
4.49 51° |
4.59 58° |
4.15 51° |
3.86 43° |
3.02 35° |
2.08 27° |
1.34 19° |
0.86 12° |
Solar insolation values - United States of America
Alabama
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.32 |
2.9 |
4.06 |
5.01 |
5.54 |
5.64 |
5.7 |
5.14 |
4.58 |
3.84 |
2.68 |
2.17 |
Upright - 0° |
2.94 |
2.85 |
3.06 |
2.67 |
2.30 |
2.15 |
2.22 |
2.46 |
3.03 |
3.72 |
3.29 |
3.00 |
58° angle Year-round tilt |
3.29 |
3.64 |
4.60 |
5.04 |
5.10 |
5.02 |
5.14 |
4.96 |
4.98 |
4.86 |
3.76 |
3.22 |
42° angle Best winter tilt |
3.45 |
3.68 |
4.46 |
4.65 |
4.52 |
4.36 |
4.49 |
4.50 |
4.75 |
4.90 |
3.92 |
3.42 |
74° angle Best summer tilt |
2.96 |
3.42 |
4.5 |
5.18 |
5.46 |
5.45 |
5.55 |
5.20 |
4.96 |
4.56 |
3.39 |
2.85 |
Tilt adjusted each month |
3.45 42° |
3.69 50° |
4.60 58° |
5.18 66° |
5.46 74° |
5.64 82° |
5.55 74° |
5.22 66° |
4.98 58° |
4.92 50° |
3.92 42° |
3.45 34° |
Alaska
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
0.40 |
1.07 |
2.22 |
3.73 |
4.95 |
5.26 |
4.86 |
3.86 |
2.46 |
1.37 |
0.58 |
0.00 |
Upright - 0° |
0.88 |
1.75 |
2.51 |
3.09 |
3.22 |
3.08 |
2.98 |
2.83 |
2.47 |
2.00 |
1.20 |
0.00 |
32° angle Year-round tilt |
0.89 |
1.89 |
2.97 |
4.06 |
4.50 |
4.47 |
4.24 |
3.81 |
3.03 |
2.21 |
1.23 |
0.00 |
16° angle Best winter tilt |
0.92 |
1.88 |
2.83 |
3.68 |
3.99 |
3.90 |
3.73 |
3.43 |
2.84 |
2.17 |
1.25 |
0.00 |
48° angle Best summer tilt |
0.82 |
1.80 |
2.97 |
4.25 |
4.93 |
4.93 |
4.66 |
4.07 |
3.09 |
2.13 |
1.14 |
0.00 |
Tilt adjusted each month |
0.92 16° |
1.90 24° |
2.97 32° |
4.27 40° |
4.93 48° |
5.35 56° |
4.66 48° |
4.16 40° |
3.03 32° |
2.21 24° |
1.25 16° |
0.00 8° |
Arizona
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
3.20 |
4.07 |
5.45 |
6.62 |
7.37 |
7.52 |
6.78 |
5.97 |
5.45 |
4.48 |
3.50 |
2.95 |
Upright - 0° |
4.63 |
4.59 |
4.29 |
3.33 |
2.57 |
2.28 |
2.34 |
2.70 |
3.60 |
4.51 |
4.76 |
4.63 |
57° angle Year-round tilt |
4.92 |
5.55 |
6.45 |
6.83 |
6.74 |
6.57 |
6.08 |
5.78 |
6.03 |
5.82 |
5.24 |
4.74 |
41° angle Best winter tilt |
5.28 |
5.74 |
6.34 |
6.33 |
5.87 |
5.58 |
5.26 |
5.22 |
5.78 |
5.93 |
5.57 |
5.14 |
73° angle Best summer tilt |
4.28 |
5.04 |
6.20 |
6.96 |
7.26 |
7.23 |
6.60 |
6.05 |
5.95 |
5.39 |
4.60 |
4.06 |
Tilt adjusted each month |
5.28 41° |
5.74 49° |
6.45 57° |
6.97 65° |
7.26 73° |
7.52 80° |
6.60 73° |
6.07 65° |
6.03 57° |
5.94 49° |
5.57 41° |
5.24 34° |
Arkansas
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.39 |
3.03 |
4.01 |
5.19 |
5.51 |
5.91 |
6.02 |
5.52 |
4.74 |
3.71 |
2.60 |
2.15 |
Upright - 0° |
3.14 |
3.09 |
3.07 |
2.80 |
2.33 |
2.22 |
2.31 |
2.64 |
3.20 |
3.62 |
3.23 |
3.02 |
55° angle Year-round tilt |
3.45 |
3.88 |
4.56 |
5.24 |
5.10 |
5.26 |
5.44 |
5.36 |
5.20 |
4.70 |
3.66 |
3.21 |
39° angle Best winter tilt |
3.64 |
3.94 |
4.44 |
4.84 |
4.52 |
4.57 |
4.76 |
4.86 |
4.98 |
4.74 |
3.82 |
3.42 |
71° angle Best summer tilt |
3.08 |
3.62 |
4.46 |
5.38 |
5.44 |
5.72 |
5.88 |
5.61 |
5.16 |
4.41 |
3.30 |
2.83 |
Tilt adjusted each month |
3.64 39° |
3.94 47° |
4.56 55° |
5.38 63° |
5.44 71° |
5.91 78° |
5.88 71° |
5.63 63° |
5.20 55° |
4.75 47° |
3.82 39° |
3.45 32° |
California
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.18 |
3.09 |
4.65 |
6.08 |
7.21 |
7.93 |
7.79 |
7.02 |
5.64 |
4.12 |
2.63 |
1.99 |
Upright - 0° |
3.35 |
3.68 |
4.09 |
3.53 |
2.96 |
2.69 |
2.82 |
3.46 |
4.34 |
4.83 |
3.96 |
3.37 |
51° angle Year-round tilt |
3.52 |
4.36 |
5.72 |
6.32 |
6.64 |
6.91 |
6.95 |
6.95 |
6.64 |
5.86 |
4.23 |
3.41 |
35° angle Best winter tilt |
3.73 |
4.46 |
5.61 |
5.83 |
5.79 |
5.84 |
5.95 |
6.25 |
6.39 |
5.98 |
4.47 |
3.66 |
67° angle Best summer tilt |
3.12 |
4.02 |
5.52 |
6.49 |
7.16 |
7.63 |
7.60 |
7.29 |
6.52 |
5.40 |
3.75 |
2.97 |
Tilt adjusted each month |
3.73 35° |
4.46 43° |
5.72 51° |
6.49 59° |
7.16 67° |
7.95 74° |
7.60 67° |
7.31 59° |
6.64 51° |
5.98 43° |
4.47 35° |
3.71 28° |
Colorado
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.41 |
3.27 |
4.49 |
5.42 |
6.28 |
6.70 |
6.35 |
5.68 |
5.03 |
3.90 |
2.67 |
2.18 |
Upright - 0° |
4.20 |
4.18 |
4.05 |
3.25 |
2.80 |
2.60 |
2.64 |
2.99 |
3.90 |
4.66 |
4.30 |
4.21 |
50° angle Year-round tilt |
4.27 |
4.85 |
5.58 |
5.62 |
5.81 |
5.90 |
5.72 |
5.60 |
5.87 |
5.60 |
4.52 |
4.12 |
34° angle Best winter tilt |
4.58 |
4.99 |
5.47 |
5.17 |
5.10 |
5.05 |
4.96 |
5.05 |
5.63 |
5.71 |
4.79 |
4.47 |
66° angle Best summer tilt |
3.72 |
4.43 |
5.39 |
5.78 |
6.24 |
6.47 |
6.21 |
5.87 |
5.79 |
5.17 |
3.98 |
3.53 |
Tilt adjusted each month |
4.58 34° |
4.99 42° |
5.58 50° |
5.78 58° |
6.24 66° |
6.73 74° |
6.21 66° |
5.89 58° |
5.87 50° |
5.71 42° |
4.79 34° |
4.56 26° |
Connecticut
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.88 |
2.73 |
3.76 |
4.52 |
5.23 |
5.80 |
5.54 |
5.00 |
4.11 |
3.01 |
1.97 |
1.63 |
Upright - 0° |
3.20 |
3.50 |
3.41 |
2.83 |
2.57 |
2.52 |
2.54 |
2.79 |
3.23 |
3.45 |
3.00 |
3.01 |
48° angle Year-round tilt |
3.29 |
4.05 |
4.62 |
4.65 |
4.85 |
5.07 |
5.01 |
4.92 |
4.73 |
4.17 |
3.21 |
3.00 |
32° angle Best winter tilt |
3.49 |
4.14 |
4.50 |
4.28 |
4.28 |
4.38 |
4.37 |
4.45 |
4.51 |
4.20 |
3.35 |
3.21 |
64° angle Best summer tilt |
2.91 |
3.73 |
4.50 |
4.80 |
5.20 |
5.53 |
5.42 |
5.16 |
4.71 |
3.92 |
2.88 |
2.61 |
Tilt adjusted each month |
3.49 32° |
4.14 40° |
4.62 48° |
4.80 56° |
5.20 64° |
5.81 72° |
5.42 64° |
5.19 56° |
4.73 48° |
4.21 40° |
3.35 32° |
3.25 24° |
Delaware
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.97 |
2.73 |
3.69 |
4.65 |
5.27 |
5.67 |
5.50 |
5.05 |
4.25 |
3.33 |
2.24 |
1.77 |
Upright - 0° |
2.99 |
3.16 |
3.10 |
2.77 |
2.46 |
2.36 |
2.40 |
2.68 |
3.15 |
3.65 |
3.21 |
2.93 |
51° angle Year-round tilt |
3.17 |
3.78 |
4.35 |
4.73 |
4.86 |
5.01 |
4.95 |
4.92 |
4.78 |
4.51 |
3.50 |
3.00 |
35° angle Best winter tilt |
3.34 |
3.84 |
4.22 |
4.36 |
4.29 |
4.34 |
4.32 |
4.44 |
4.56 |
4.54 |
3.66 |
3.20 |
67° angle Best summer tilt |
2.82 |
3.52 |
4.26 |
4.89 |
5.21 |
5.47 |
5.36 |
5.17 |
4.77 |
4.23 |
3.14 |
2.64 |
Tilt adjusted each month |
3.34 35° |
3.85 43° |
4.35 51° |
4.89 59° |
5.21 67° |
5.68 74° |
5.36 67° |
5.20 59° |
4.78 51° |
4.56 43° |
3.66 35° |
3.23 28° |
Florida
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
3.56 |
4.44 |
5.29 |
6.11 |
6.49 |
5.97 |
5.55 |
5.26 |
4.76 |
4.52 |
3.78 |
3.35 |
Upright - 0° |
4.03 |
4.07 |
3.44 |
2.62 |
2.06 |
1.88 |
1.91 |
2.15 |
2.68 |
3.68 |
4.04 |
4.07 |
63° angle Year-round tilt |
4.66 |
5.39 |
5.80 |
6.11 |
5.98 |
5.38 |
5.08 |
5.06 |
4.96 |
5.27 |
4.85 |
4.51 |
47° angle Best winter tilt |
4.96 |
5.56 |
5.69 |
5.68 |
5.28 |
4.69 |
4.50 |
4.62 |
4.75 |
5.33 |
5.11 |
4.85 |
79° angle Best summer tilt |
4.11 |
4.94 |
5.61 |
6.23 |
6.39 |
5.82 |
5.45 |
5.26 |
4.93 |
4.93 |
4.32 |
3.92 |
Tilt adjusted each month |
4.96 47° |
5.56 55° |
5.80 63° |
6.23 71° |
6.39 79° |
5.97 86° |
5.45 79° |
5.28 71° |
4.96 63° |
5.34 55° |
5.11 47° |
4.92 40° |
Georgia
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.50 |
3.12 |
4.28 |
5.19 |
5.80 |
5.59 |
5.72 |
5.17 |
4.46 |
3.91 |
2.82 |
2.36 |
Upright - 0° |
3.21 |
3.14 |
3.23 |
2.74 |
2.34 |
2.13 |
2.21 |
2.46 |
2.92 |
3.76 |
3.48 |
3.32 |
56° angle Year-round tilt |
3.55 |
3.96 |
4.86 |
5.24 |
5.36 |
5.00 |
5.18 |
5.01 |
4.82 |
4.92 |
3.96 |
3.52 |
40° angle Best winter tilt |
3.74 |
4.02 |
4.74 |
4.86 |
4.74 |
4.37 |
4.55 |
4.55 |
4.60 |
4.97 |
4.15 |
3.76 |
72° angle Best summer tilt |
3.17 |
3.69 |
4.74 |
5.38 |
5.72 |
5.42 |
5.58 |
5.23 |
4.80 |
4.60 |
3.55 |
3.09 |
Tilt adjusted each month |
3.74 40° |
4.03 48° |
4.86 56° |
5.38 64° |
5.72 72° |
5.59 80° |
5.58 72° |
5.25 64° |
4.82 56° |
4.98 48° |
4.15 40° |
3.80 32° |
Hawaii
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
4.09 |
5.06 |
5.85 |
6.58 |
6.97 |
7.35 |
7.21 |
6.88 |
6.36 |
5.41 |
4.34 |
3.90 |
Upright - 0° |
4.06 |
4.12 |
3.33 |
2.33 |
1.77 |
2.80 |
1.69 |
2.01 |
3.00 |
3.96 |
4.22 |
4.12 |
69° angle Year-round tilt |
4.98 |
5.84 |
6.24 |
6.50 |
6.43 |
7.37 |
6.52 |
6.63 |
6.60 |
6.10 |
5.24 |
4.83 |
53° angle Best winter tilt |
5.29 |
6.03 |
6.13 |
6.04 |
5.65 |
6.92 |
5.65 |
6.03 |
6.34 |
6.20 |
5.56 |
5.19 |
85° angle Best summer tilt |
4.40 |
5.34 |
6.03 |
6.62 |
6.89 |
7.43 |
7.08 |
6.88 |
6.50 |
5.67 |
4.65 |
4.21 |
Tilt adjusted each month |
5.29 53° |
6.03 61° |
6.24 69° |
6.63 77° |
6.89 85° |
7.46 92° |
7.08 85° |
6.89 77° |
6.60 69° |
6.21 61° |
5.56 53° |
5.27 46° |
Idaho
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.72 |
2.66 |
4.07 |
5.38 |
6.36 |
7.24 |
7.37 |
6.44 |
4.99 |
3.43 |
1.97 |
1.49 |
Upright - 0° |
3.17 |
3.67 |
4.01 |
3.53 |
3.08 |
2.98 |
3.18 |
3.66 |
4.33 |
4.56 |
3.35 |
3.00 |
47° angle Year-round tilt |
3.21 |
4.15 |
5.28 |
5.72 |
5.92 |
6.26 |
6.56 |
6.51 |
6.14 |
5.28 |
3.49 |
2.96 |
31° angle Best winter tilt |
3.41 |
4.25 |
5.16 |
5.26 |
5.17 |
5.31 |
5.61 |
5.85 |
5.89 |
5.38 |
3.67 |
3.17 |
63° angle Best summer tilt |
2.83 |
3.82 |
5.10 |
5.88 |
6.38 |
6.89 |
7.16 |
6.83 |
6.04 |
4.88 |
3.11 |
2.57 |
Tilt adjusted each month |
3.41 31° |
4.25 39° |
5.28 47° |
5.88 55° |
6.38 63° |
7.26 70° |
7.16 63° |
6.85 55° |
6.14 47° |
5.38 39° |
3.67 31° |
3.21 24° |
Illinois
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.92 |
2.55 |
3.62 |
4.69 |
5.40 |
5.90 |
6.12 |
5.38 |
4.57 |
3.32 |
2.10 |
1.71 |
Upright - 0° |
2.91 |
2.91 |
3.06 |
2.83 |
2.54 |
2.44 |
2.59 |
2.86 |
3.48 |
3.70 |
2.95 |
2.84 |
50° angle Year-round tilt |
3.08 |
3.48 |
4.28 |
4.80 |
5.01 |
5.23 |
5.52 |
5.29 |
5.24 |
4.53 |
3.22 |
2.90 |
34° angle Best winter tilt |
3.24 |
3.53 |
4.15 |
4.42 |
4.42 |
4.52 |
4.80 |
4.78 |
5.01 |
4.58 |
3.36 |
3.09 |
66° angle Best summer tilt |
2.74 |
3.25 |
4.19 |
4.95 |
5.36 |
5.71 |
5.99 |
5.54 |
5.19 |
4.24 |
2.90 |
2.55 |
Tilt adjusted each month |
3.24 34° |
3.54 42° |
4.28 50° |
4.95 58° |
5.36 66° |
5.92 74° |
5.99 66° |
5.57 58° |
5.24 50° |
4.59 42° |
3.36 34° |
3.12 26° |
Indiana
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.83 |
2.54 |
3.55 |
4.49 |
5.19 |
5.91 |
5.98 |
5.24 |
4.55 |
3.26 |
2.02 |
1.57 |
Upright - 0° |
2.70 |
2.89 |
2.99 |
2.70 |
2.46 |
2.44 |
2.56 |
2.80 |
3.46 |
3.60 |
2.78 |
2.47 |
50° angle Year-round tilt |
2.87 |
3.46 |
4.18 |
4.57 |
4.80 |
5.24 |
5.40 |
5.15 |
5.21 |
4.42 |
3.05 |
2.56 |
34° angle Best winter tilt |
3.02 |
3.51 |
4.05 |
4.21 |
4.25 |
4.53 |
4.70 |
4.65 |
4.98 |
4.46 |
3.17 |
2.72 |
66° angle Best summer tilt |
2.57 |
3.24 |
4.10 |
4.71 |
5.14 |
5.72 |
5.85 |
5.39 |
5.17 |
4.15 |
2.76 |
2.27 |
Tilt adjusted each month |
3.02 34° |
3.52 42° |
4.18 50° |
4.72 58° |
5.14 66° |
5.93 74° |
5.85 66° |
5.42 58° |
5.21 50° |
4.48 42° |
3.17 34° |
2.74 26° |
Iowa
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.91 |
2.56 |
3.62 |
4.56 |
5.39 |
6.12 |
6.02 |
5.32 |
4.41 |
3.14 |
2.02 |
1.64 |
Upright - 0° |
3.26 |
3.15 |
3.23 |
2.84 |
2.62 |
2.59 |
2.67 |
2.94 |
3.50 |
3.67 |
3.10 |
3.04 |
48° angle Year-round tilt |
3.35 |
3.68 |
4.40 |
4.68 |
4.99 |
5.33 |
5.43 |
5.26 |
5.13 |
4.42 |
3.31 |
3.04 |
32° angle Best winter tilt |
3.55 |
3.74 |
4.27 |
4.31 |
4.40 |
4.59 |
4.71 |
4.74 |
4.90 |
4.46 |
3.46 |
3.25 |
64° angle Best summer tilt |
2.96 |
3.42 |
4.30 |
4.84 |
5.36 |
5.83 |
5.90 |
5.52 |
5.09 |
4.14 |
2.97 |
2.65 |
Tilt adjusted each month |
3.55 32° |
3.75 40° |
4.40 48° |
4.84 56° |
5.36 64° |
6.13 72° |
5.90 64° |
5.55 56° |
5.13 48° |
4.47 40° |
3.46 32° |
3.29 24° |
Kansas
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.15 |
2.72 |
3.91 |
4.80 |
5.61 |
6.15 |
6.37 |
5.48 |
4.67 |
3.41 |
2.30 |
1.92 |
Upright - 0° |
3.40 |
3.13 |
3.32 |
2.84 |
2.56 |
2.46 |
2.60 |
2.86 |
3.50 |
3.76 |
3.32 |
3.32 |
51° angle Year-round tilt |
3.57 |
3.75 |
4.66 |
4.89 |
5.16 |
5.41 |
5.70 |
5.36 |
5.33 |
4.64 |
3.61 |
3.36 |
35° angle Best winter tilt |
3.78 |
3.81 |
4.53 |
4.50 |
4.54 |
4.65 |
4.93 |
4.83 |
5.09 |
4.68 |
3.78 |
3.60 |
67° angle Best summer tilt |
3.16 |
3.50 |
4.55 |
5.05 |
5.54 |
5.93 |
6.21 |
5.63 |
5.29 |
4.35 |
3.24 |
2.93 |
Tilt adjusted each month |
3.78 35° |
3.81 43° |
4.66 51° |
5.06 59° |
5.54 67° |
6.17 74° |
6.21 67° |
5.66 59° |
5.33 51° |
4.69 43° |
3.78 35° |
3.64 28° |
Louisiana
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.59 |
3.25 |
4.31 |
5.21 |
5.79 |
5.65 |
5.66 |
5.30 |
4.72 |
4.03 |
3.04 |
2.56 |
Upright - 0° |
2.95 |
3.02 |
3.01 |
2.57 |
2.19 |
2.00 |
2.07 |
2.34 |
2.89 |
3.55 |
3.42 |
3.22 |
60° angle Year-round tilt |
3.41 |
3.95 |
4.76 |
5.23 |
5.35 |
5.07 |
5.14 |
5.11 |
5.02 |
4.85 |
4.03 |
3.54 |
44° angle Best winter tilt |
3.57 |
4.00 |
4.63 |
4.86 |
4.75 |
4.43 |
4.53 |
4.65 |
4.80 |
4.89 |
4.21 |
3.77 |
76° angle Best summer tilt |
3.08 |
3.69 |
4.65 |
5.35 |
5.71 |
5.48 |
5.53 |
5.33 |
4.99 |
4.55 |
3.63 |
3.13 |
Tilt adjusted each month |
3.57 44° |
4.01 52° |
4.76 60° |
5.35 68° |
5.71 76° |
5.65 84° |
5.53 76° |
5.35 68° |
5.02 60° |
4.90 52° |
4.21 44° |
3.80 36° |
Maine
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.69 |
2.57 |
3.64 |
4.43 |
4.87 |
5.35 |
5.28 |
4.85 |
3.78 |
2.56 |
1.60 |
1.33 |
Upright - 0° |
3.25 |
3.61 |
3.52 |
2.91 |
2.52 |
2.50 |
2.56 |
2.84 |
3.10 |
3.01 |
2.51 |
2.57 |
46° angle Year-round tilt |
3.28 |
4.07 |
4.63 |
4.59 |
4.50 |
4.64 |
4.69 |
4.80 |
4.39 |
3.60 |
2.68 |
2.58 |
30° angle Best winter tilt |
3.48 |
4.16 |
4.50 |
4.21 |
3.96 |
4.01 |
4.09 |
4.32 |
4.17 |
3.60 |
2.78 |
2.74 |
62° angle Best summer tilt |
2.88 |
3.75 |
4.52 |
4.76 |
4.84 |
5.09 |
5.10 |
5.05 |
4.39 |
3.41 |
2.43 |
2.27 |
Tilt adjusted each month |
3.48 30° |
4.16 38° |
4.63 46° |
4.76 54° |
4.84 62° |
5.37 70° |
5.10 62° |
5.09 54° |
4.39 46° |
3.62 38° |
2.78 30° |
2.76 22° |
Maryland
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.94 |
2.68 |
3.67 |
4.63 |
5.31 |
5.58 |
5.53 |
4.94 |
4.19 |
3.33 |
2.19 |
1.71 |
Upright - 0° |
2.89 |
3.06 |
3.06 |
2.75 |
2.47 |
2.33 |
2.40 |
2.62 |
3.09 |
3.63 |
3.08 |
2.75 |
51° angle Year-round tilt |
3.09 |
3.68 |
4.31 |
4.70 |
4.89 |
4.93 |
4.97 |
4.80 |
4.70 |
4.50 |
3.37 |
2.84 |
35° angle Best winter tilt |
3.24 |
3.73 |
4.18 |
4.33 |
4.31 |
4.27 |
4.34 |
4.34 |
4.47 |
4.53 |
3.52 |
3.02 |
67° angle Best summer tilt |
2.76 |
3.44 |
4.23 |
4.86 |
5.24 |
5.38 |
5.39 |
5.04 |
4.69 |
4.22 |
3.04 |
2.51 |
Tilt adjusted each month |
3.24 35° |
3.74 43° |
4.31 51° |
4.87 59° |
5.24 67° |
5.59 74° |
5.39 67° |
5.08 59° |
4.70 51° |
4.55 43° |
3.52 35° |
3.04 28° |
Massachusetts
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.80 |
2.62 |
3.61 |
4.46 |
5.13 |
5.50 |
5.60 |
4.99 |
4.04 |
2.93 |
1.89 |
1.54 |
Upright - 0° |
3.15 |
3.40 |
3.30 |
2.83 |
2.56 |
2.47 |
2.59 |
2.81 |
3.22 |
3.41 |
2.94 |
2.91 |
48° angle Year-round tilt |
3.22 |
3.91 |
4.44 |
4.59 |
4.75 |
4.79 |
5.05 |
4.91 |
4.67 |
4.10 |
3.13 |
2.90 |
32° angle Best winter tilt |
3.42 |
3.99 |
4.32 |
4.22 |
4.19 |
4.15 |
4.40 |
4.43 |
4.45 |
4.12 |
3.27 |
3.10 |
64° angle Best summer tilt |
2.85 |
3.62 |
4.34 |
4.74 |
5.10 |
5.24 |
5.49 |
5.16 |
4.66 |
3.86 |
2.82 |
2.53 |
Tilt adjusted each month |
3.42 32° |
3.99 40° |
4.44 48° |
4.75 56° |
5.10 64° |
5.51 72° |
5.49 64° |
5.19 56° |
4.67 48° |
4.14 40° |
3.27 32° |
3.14 24° |
Michigan
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.78 |
2.51 |
3.44 |
4.45 |
5.24 |
6.07 |
5.93 |
5.03 |
4.13 |
2.79 |
1.69 |
1.41 |
Upright - 0° |
3.13 |
3.22 |
3.11 |
2.84 |
2.61 |
2.64 |
2.70 |
2.86 |
3.33 |
3.20 |
2.47 |
2.55 |
47° angle Year-round tilt |
3.20 |
3.71 |
4.20 |
4.59 |
4.86 |
5.29 |
5.36 |
4.97 |
4.81 |
3.86 |
2.67 |
2.56 |
31° angle Best winter tilt |
3.39 |
3.78 |
4.07 |
4.22 |
4.29 |
4.55 |
4.65 |
4.49 |
4.59 |
3.87 |
2.77 |
2.73 |
63° angle Best summer tilt |
2.83 |
3.44 |
4.11 |
4.74 |
5.21 |
5.78 |
5.82 |
5.22 |
4.78 |
3.64 |
2.43 |
2.25 |
Tilt adjusted each month |
3.39 31° |
3.78 39° |
4.20 47° |
4.74 55° |
5.21 63° |
6.09 70° |
5.82 63° |
5.25 55° |
4.81 47° |
3.89 39° |
2.77 31° |
2.75 24° |
Minnesota
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.71 |
2.55 |
3.44 |
4.54 |
5.32 |
5.96 |
6.05 |
5.19 |
4.00 |
2.78 |
1.76 |
1.37 |
Upright - 0° |
3.41 |
3.65 |
3.33 |
3.03 |
2.75 |
2.73 |
2.87 |
3.08 |
3.39 |
3.49 |
3.03 |
2.81 |
45° angle Year-round tilt |
3.39 |
4.08 |
4.36 |
4.76 |
4.96 |
5.19 |
5.40 |
5.20 |
4.76 |
4.08 |
3.15 |
2.77 |
29° angle Best winter tilt |
3.62 |
4.18 |
4.24 |
4.37 |
4.36 |
4.47 |
4.68 |
4.68 |
4.54 |
4.12 |
3.30 |
2.97 |
61° angle Best summer tilt |
2.97 |
3.74 |
4.25 |
4.91 |
5.33 |
5.68 |
5.87 |
5.46 |
4.73 |
3.83 |
2.82 |
2.42 |
Tilt adjusted each month |
3.62 29° |
4.18 37° |
4.36 45° |
4.92 53° |
5.33 61° |
5.99 68° |
5.87 61° |
5.48 53° |
4.76 45° |
4.13 37° |
3.30 29° |
3.00 22° |
Mississippi
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.52 |
3.24 |
4.24 |
5.34 |
5.89 |
5.98 |
5.80 |
5.36 |
4.75 |
3.99 |
2.94 |
2.39 |
Upright - 0° |
3.08 |
3.20 |
3.09 |
2.72 |
2.30 |
2.12 |
2.17 |
2.46 |
3.04 |
3.71 |
3.53 |
3.17 |
58° angle Year-round tilt |
3.48 |
4.07 |
4.75 |
5.39 |
5.43 |
5.33 |
5.25 |
5.17 |
5.12 |
4.94 |
4.05 |
3.44 |
42° angle Best winter tilt |
3.66 |
4.14 |
4.62 |
5.00 |
4.80 |
4.62 |
4.60 |
4.70 |
4.90 |
4.99 |
4.24 |
3.65 |
74° angle Best summer tilt |
3.12 |
3.79 |
4.64 |
5.52 |
5.80 |
5.79 |
5.66 |
5.41 |
5.09 |
4.63 |
3.64 |
3.03 |
Tilt adjusted each month |
3.66 42° |
4.14 50° |
4.75 58° |
5.52 66° |
5.80 74° |
5.98 82° |
5.66 74° |
5.43 66° |
5.12 58° |
5.00 50° |
4.24 42° |
3.69 34° |
Missouri
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.09 |
2.71 |
3.85 |
4.94 |
5.53 |
5.95 |
6.18 |
5.52 |
4.62 |
3.42 |
2.23 |
1.89 |
Upright - 0° |
3.13 |
3.04 |
3.21 |
2.90 |
2.52 |
2.40 |
2.54 |
2.85 |
3.42 |
3.70 |
3.07 |
3.10 |
51° angle Year-round tilt |
3.32 |
3.67 |
4.54 |
5.05 |
5.11 |
5.27 |
5.57 |
5.41 |
5.24 |
4.59 |
3.37 |
3.17 |
35° angle Best winter tilt |
3.51 |
3.72 |
4.41 |
4.65 |
4.51 |
4.55 |
4.84 |
4.89 |
5.01 |
4.63 |
3.52 |
3.38 |
67° angle Best summer tilt |
2.95 |
3.42 |
4.43 |
5.20 |
5.47 |
5.74 |
6.04 |
5.67 |
5.20 |
4.30 |
3.04 |
2.77 |
Tilt adjusted each month |
3.51 35° |
3.73 43° |
4.54 51° |
5.20 59° |
5.47 67° |
5.96 74° |
6.04 67° |
5.70 59° |
5.24 51° |
4.65 43° |
3.52 35° |
3.42 28° |
Montana
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.64 |
2.51 |
3.65 |
4.72 |
5.60 |
6.31 |
6.58 |
5.70 |
4.30 |
2.83 |
1.83 |
1.37 |
Upright - 0° |
2.59 |
3.19 |
3.41 |
3.22 |
2.95 |
2.94 |
3.18 |
3.45 |
3.62 |
3.31 |
2.73 |
2.25 |
43° angle Year-round tilt |
2.73 |
3.67 |
4.48 |
4.98 |
5.21 |
5.48 |
5.87 |
5.71 |
5.04 |
3.95 |
2.94 |
2.34 |
27° angle Best winter tilt |
2.83 |
3.69 |
4.33 |
4.58 |
4.59 |
4.71 |
5.08 |
5.14 |
4.79 |
3.94 |
3.03 |
2.44 |
59° angle Best summer tilt |
2.48 |
3.45 |
4.41 |
5.14 |
5.61 |
6.00 |
6.39 |
6.00 |
5.04 |
3.76 |
2.70 |
2.12 |
Tilt adjusted each month |
2.83 27° |
3.71 35° |
4.48 43° |
5.15 51° |
5.61 59° |
6.34 66° |
6.39 59° |
6.04 51° |
5.04 43° |
3.97 35° |
3.03 27° |
2.45 20° |
Nebraska
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.09 |
2.68 |
3.83 |
4.78 |
5.57 |
6.35 |
6.35 |
5.48 |
4.63 |
3.35 |
2.26 |
1.86 |
Upright - 0° |
3.55 |
3.26 |
3.39 |
2.93 |
2.64 |
2.60 |
2.71 |
2.97 |
3.63 |
3.90 |
3.51 |
3.50 |
49° angle Year-round tilt |
3.65 |
3.82 |
4.65 |
4.91 |
5.16 |
5.54 |
5.73 |
5.41 |
5.38 |
4.70 |
3.72 |
3.47 |
33° angle Best winter tilt |
3.88 |
3.90 |
4.53 |
4.53 |
4.55 |
4.77 |
4.96 |
4.89 |
5.15 |
4.76 |
3.92 |
3.74 |
65° angle Best summer tilt |
3.20 |
3.55 |
4.53 |
5.07 |
5.54 |
6.06 |
6.22 |
5.67 |
5.33 |
4.39 |
3.32 |
3.00 |
Tilt adjusted each month |
3.88 33° |
3.90 41° |
4.65 49° |
5.07 57° |
5.54 65° |
6.36 72° |
6.22 65° |
5.70 57° |
5.38 49° |
4.77 41° |
3.92 33° |
3.79 26° |
Nevada
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.29 |
3.15 |
4.61 |
5.85 |
7.01 |
7.77 |
7.76 |
6.89 |
5.60 |
4.06 |
2.60 |
2.11 |
Upright - 0° |
3.84 |
3.94 |
4.16 |
3.48 |
2.98 |
2.74 |
2.90 |
3.49 |
4.42 |
4.91 |
4.10 |
3.95 |
51° angle Year-round tilt |
3.95 |
4.60 |
5.75 |
6.10 |
6.47 |
6.77 |
6.93 |
6.85 |
6.67 |
5.89 |
4.33 |
3.91 |
35° angle Best winter tilt |
4.21 |
4.72 |
5.64 |
5.61 |
5.64 |
5.72 |
5.93 |
6.15 |
6.41 |
6.01 |
4.58 |
4.22 |
67° angle Best summer tilt |
3.46 |
4.22 |
5.55 |
6.26 |
6.97 |
7.47 |
7.58 |
7.17 |
6.55 |
5.42 |
3.83 |
3.36 |
Tilt adjusted each month |
4.21 35° |
4.72 43° |
5.75 51° |
6.26 59° |
6.97 67° |
7.79 74° |
7.58 67° |
7.20 59° |
6.67 51° |
6.01 43° |
4.58 35° |
4.30 28° |
New Hampshire
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.74 |
2.62 |
3.61 |
4.43 |
4.92 |
5.42 |
5.47 |
4.91 |
3.92 |
2.72 |
1.71 |
1.46 |
Upright - 0° |
3.17 |
3.54 |
3.38 |
2.85 |
2.51 |
2.48 |
2.58 |
2.82 |
3.16 |
3.17 |
2.63 |
2.86 |
47° angle Year-round tilt |
3.23 |
4.03 |
4.51 |
4.57 |
4.55 |
4.71 |
4.90 |
4.85 |
4.54 |
3.80 |
2.81 |
2.84 |
31° angle Best winter tilt |
3.42 |
4.12 |
4.38 |
4.20 |
4.01 |
4.08 |
4.26 |
4.36 |
4.31 |
3.81 |
2.92 |
3.03 |
63° angle Best summer tilt |
2.85 |
3.72 |
4.40 |
4.73 |
4.89 |
5.16 |
5.32 |
5.10 |
4.53 |
3.59 |
2.54 |
2.47 |
Tilt adjusted each month |
3.42 31° |
4.12 39° |
4.51 47° |
4.74 55° |
4.89 63° |
5.43 70° |
5.32 63° |
5.13 55° |
4.54 47° |
3.83 39° |
2.92 31° |
3.07 24° |
New Jersey
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.92 |
2.71 |
3.69 |
4.57 |
5.21 |
5.61 |
5.51 |
4.97 |
4.15 |
3.13 |
2.07 |
1.66 |
Upright - 0° |
3.03 |
3.25 |
3.18 |
2.77 |
2.49 |
2.39 |
2.45 |
2.69 |
3.15 |
3.47 |
2.99 |
2.83 |
50° angle Year-round tilt |
3.18 |
3.84 |
4.41 |
4.66 |
4.81 |
4.96 |
4.97 |
4.85 |
4.70 |
4.26 |
3.24 |
2.88 |
34° angle Best winter tilt |
3.35 |
3.91 |
4.28 |
4.28 |
4.25 |
4.29 |
4.33 |
4.38 |
4.48 |
4.28 |
3.38 |
3.07 |
66° angle Best summer tilt |
2.82 |
3.57 |
4.32 |
4.81 |
5.16 |
5.42 |
5.38 |
5.10 |
4.69 |
4.01 |
2.93 |
2.53 |
Tilt adjusted each month |
3.35 34° |
3.91 42° |
4.41 50° |
4.82 58° |
5.16 66° |
5.63 74° |
5.38 66° |
5.13 58° |
4.70 50° |
4.30 42° |
3.38 34° |
3.10 26° |
New Mexico
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
3.04 |
3.85 |
5.14 |
6.32 |
7.04 |
7.22 |
6.51 |
5.81 |
5.41 |
4.39 |
3.29 |
2.81 |
Upright - 0° |
4.80 |
4.49 |
4.27 |
3.39 |
2.70 |
2.42 |
2.44 |
2.79 |
3.80 |
4.73 |
4.83 |
4.87 |
54° angle Year-round tilt |
4.98 |
5.39 |
6.20 |
6.48 |
6.47 |
6.33 |
5.85 |
5.66 |
6.11 |
5.93 |
5.18 |
4.85 |
38° angle Best winter tilt |
5.36 |
5.56 |
6.10 |
5.98 |
5.66 |
5.40 |
5.08 |
5.12 |
5.87 |
6.05 |
5.52 |
5.28 |
70° angle Best summer tilt |
4.31 |
4.91 |
5.96 |
6.65 |
6.96 |
6.95 |
6.34 |
5.92 |
6.02 |
5.47 |
4.54 |
4.13 |
Tilt adjusted each month |
5.36 38° |
5.56 46° |
6.20 54° |
6.65 62° |
6.96 70° |
7.22 78° |
6.34 70° |
5.95 62° |
6.11 54° |
6.05 46° |
5.52 38° |
5.40 30° |
New York
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.74 |
2.60 |
3.57 |
4.34 |
5.04 |
5.64 |
5.55 |
4.97 |
3.95 |
2.80 |
1.76 |
1.47 |
Upright - 0° |
3.02 |
3.39 |
3.27 |
2.76 |
2.54 |
2.52 |
2.58 |
2.82 |
3.15 |
3.22 |
2.63 |
2.73 |
47° angle Year-round tilt |
3.09 |
3.89 |
4.40 |
4.46 |
4.67 |
4.92 |
5.02 |
4.91 |
4.56 |
3.88 |
2.83 |
2.73 |
31° angle Best winter tilt |
3.28 |
3.97 |
4.27 |
4.10 |
4.13 |
4.26 |
4.37 |
4.43 |
4.35 |
3.89 |
2.94 |
2.91 |
63° angle Best summer tilt |
2.74 |
3.60 |
4.29 |
4.61 |
5.01 |
5.37 |
5.44 |
5.16 |
4.55 |
3.66 |
2.56 |
2.39 |
Tilt adjusted each month |
3.28 31° |
3.97 39° |
4.40 47° |
4.62 55° |
5.01 63° |
5.65 70° |
5.44 63° |
5.19 55° |
4.56 47° |
3.91 39° |
2.94 31° |
2.94 24° |
North Carolina
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.43 |
3.05 |
4.20 |
5.22 |
5.73 |
5.80 |
5.68 |
5.08 |
4.43 |
3.76 |
2.73 |
2.30 |
Upright - 0° |
3.39 |
3.24 |
3.33 |
2.87 |
2.43 |
2.25 |
2.30 |
2.52 |
3.05 |
3.82 |
3.64 |
3.56 |
54° angle Year-round tilt |
3.66 |
4.00 |
4.87 |
5.29 |
5.29 |
5.16 |
5.15 |
4.93 |
4.86 |
4.87 |
4.03 |
3.67 |
38° angle Best winter tilt |
3.87 |
4.07 |
4.75 |
4.89 |
4.69 |
4.49 |
4.51 |
4.47 |
4.64 |
4.93 |
4.24 |
3.94 |
70° angle Best summer tilt |
3.24 |
3.72 |
4.74 |
5.44 |
5.66 |
5.61 |
5.55 |
5.15 |
4.84 |
4.55 |
3.60 |
3.20 |
Tilt adjusted each month |
3.87 38° |
4.07 46° |
4.87 54° |
5.44 62° |
5.66 70° |
5.80 78° |
5.55 70° |
5.18 62° |
4.86 54° |
4.94 46° |
4.24 38° |
4 30° |
North Dakota
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.48 |
2.35 |
3.47 |
4.77 |
5.72 |
6.26 |
6.49 |
5.48 |
4.06 |
2.73 |
1.71 |
1.27 |
Upright - 0° |
2.36 |
3.02 |
3.29 |
3.29 |
3.06 |
2.98 |
3.22 |
3.39 |
3.47 |
3.25 |
2.61 |
2.15 |
43° angle Year-round tilt |
2.49 |
3.46 |
4.28 |
5.01 |
5.27 |
5.43 |
5.79 |
5.50 |
4.78 |
3.85 |
2.80 |
2.22 |
27° angle Best winter tilt |
2.58 |
3.48 |
4.13 |
4.60 |
4.63 |
4.67 |
5.01 |
4.95 |
4.54 |
3.83 |
2.88 |
2.32 |
59° angle Best summer tilt |
2.28 |
3.26 |
4.22 |
5.19 |
5.68 |
5.96 |
6.30 |
5.78 |
4.78 |
3.67 |
2.57 |
2.01 |
Tilt adjusted each month |
2.58 27° |
3.50 35° |
4.28 43° |
5.19 51° |
5.68 59° |
6.30 66° |
6.30 59° |
5.82 51° |
4.78 43° |
3.87 35° |
2.88 27° |
2.32 20° |
Ohio
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.77 |
2.49 |
3.31 |
4.47 |
5.18 |
5.64 |
5.76 |
5.11 |
4.26 |
3.08 |
1.86 |
1.46 |
Upright - 0° |
2.64 |
2.86 |
2.76 |
2.70 |
2.47 |
2.39 |
2.51 |
2.74 |
3.23 |
3.37 |
2.51 |
2.28 |
50° angle Year-round tilt |
2.81 |
3.43 |
3.86 |
4.54 |
4.77 |
4.98 |
5.18 |
4.99 |
4.84 |
4.16 |
2.78 |
2.38 |
34° angle Best winter tilt |
2.95 |
3.47 |
3.73 |
4.17 |
4.21 |
4.31 |
4.50 |
4.50 |
4.61 |
4.18 |
2.88 |
2.51 |
66° angle Best summer tilt |
2.53 |
3.21 |
3.80 |
4.69 |
5.12 |
5.44 |
5.62 |
5.24 |
4.82 |
3.92 |
2.54 |
2.12 |
Tilt adjusted each month |
2.95 34° |
3.47 42° |
3.86 50° |
4.70 58° |
5.12 66° |
5.66 74° |
5.62 66° |
5.28 58° |
4.84 50° |
4.20 42° |
2.88 34° |
2.52 26° |
Oklahoma
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.59 |
3.20 |
4.29 |
5.40 |
5.84 |
6.32 |
6.73 |
5.86 |
4.81 |
3.72 |
2.75 |
2.33 |
Upright - 0° |
3.70 |
3.43 |
3.39 |
2.94 |
2.44 |
2.31 |
2.46 |
2.79 |
3.31 |
3.73 |
3.64 |
3.59 |
54° angle Year-round tilt |
3.97 |
4.23 |
4.98 |
5.47 |
5.38 |
5.59 |
6.03 |
5.70 |
5.32 |
4.79 |
4.05 |
3.71 |
38° angle Best winter tilt |
4.21 |
4.31 |
4.86 |
5.05 |
4.75 |
4.82 |
5.22 |
5.15 |
5.09 |
4.83 |
4.25 |
3.98 |
70° angle Best summer tilt |
3.50 |
3.92 |
4.85 |
5.63 |
5.76 |
6.10 |
6.55 |
5.97 |
5.28 |
4.49 |
3.62 |
3.23 |
Tilt adjusted each month |
4.21 38° |
4.31 46° |
4.98 54° |
5.63 62° |
5.76 70° |
6.33 78° |
6.55 70° |
5.99 62° |
5.32 54° |
4.85 46° |
4.25 38° |
4.04 30° |
Oregon
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.41 |
2.24 |
3.26 |
4.33 |
5.26 |
6.19 |
6.85 |
6.04 |
4.55 |
2.82 |
1.49 |
1.16 |
Upright - 0° |
2.40 |
2.91 |
3.03 |
2.83 |
2.68 |
2.74 |
3.06 |
3.48 |
3.91 |
3.47 |
2.23 |
2.04 |
46° angle Year-round tilt |
2.49 |
3.35 |
4.02 |
4.47 |
4.86 |
5.35 |
6.07 |
6.07 |
5.53 |
4.10 |
2.41 |
2.09 |
30° angle Best winter tilt |
2.61 |
3.39 |
3.89 |
4.10 |
4.27 |
4.58 |
5.20 |
5.44 |
5.28 |
4.12 |
2.49 |
2.20 |
62° angle Best summer tilt |
2.23 |
3.12 |
3.95 |
4.64 |
5.23 |
5.88 |
6.63 |
6.39 |
5.47 |
3.85 |
2.20 |
1.86 |
Tilt adjusted each month |
2.61 30° |
3.40 38° |
4.02 46° |
4.64 54° |
5.23 62° |
6.22 70° |
6.63 62° |
6.42 54° |
5.53 46° |
4.14 38° |
2.49 30° |
2.21 22° |
Pennsylvania
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.87 |
2.65 |
3.52 |
4.32 |
5.11 |
5.44 |
5.50 |
4.86 |
4.03 |
3.07 |
1.97 |
1.58 |
Upright - 0° |
2.91 |
3.16 |
3.00 |
2.63 |
2.46 |
2.35 |
2.45 |
2.64 |
3.05 |
3.39 |
2.78 |
2.62 |
50° angle Year-round tilt |
3.07 |
3.74 |
4.17 |
4.38 |
4.71 |
4.82 |
4.96 |
4.74 |
4.55 |
4.16 |
3.03 |
2.69 |
34° angle Best winter tilt |
3.23 |
3.80 |
4.04 |
4.03 |
4.17 |
4.18 |
4.33 |
4.28 |
4.33 |
4.18 |
3.16 |
2.86 |
66° angle Best summer tilt |
2.73 |
3.48 |
4.09 |
4.53 |
5.05 |
5.26 |
5.37 |
4.98 |
4.54 |
3.92 |
2.75 |
2.38 |
Tilt adjusted each month |
3.23 34° |
3.80 42° |
4.17 50° |
4.54 58° |
5.05 66° |
5.46 74° |
5.37 66° |
5.01 58° |
4.55 50° |
4.20 42° |
3.16 34° |
2.88 26° |
Rhode Island
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.89 |
2.69 |
3.75 |
4.54 |
5.31 |
5.76 |
5.57 |
5.07 |
4.13 |
3.07 |
1.98 |
1.62 |
Upright - 0° |
3.25 |
3.44 |
3.40 |
2.85 |
2.60 |
2.52 |
2.55 |
2.83 |
3.26 |
3.58 |
3.04 |
2.99 |
48° angle Year-round tilt |
3.33 |
3.97 |
4.61 |
4.67 |
4.93 |
5.04 |
5.04 |
5.01 |
4.76 |
4.31 |
3.24 |
2.98 |
32° angle Best winter tilt |
3.53 |
4.06 |
4.49 |
4.30 |
4.35 |
4.36 |
4.40 |
4.52 |
4.55 |
4.34 |
3.39 |
3.19 |
64° angle Best summer tilt |
2.93 |
3.67 |
4.49 |
4.82 |
5.28 |
5.49 |
5.45 |
5.25 |
4.74 |
4.03 |
2.91 |
2.60 |
Tilt adjusted each month |
3.53 32° |
4.06 40° |
4.61 48° |
4.82 56° |
5.28 64° |
5.77 72° |
5.45 64° |
5.28 56° |
4.76 48° |
4.36 40° |
3.39 32° |
3.23 24° |
South Carolina
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.52 |
3.14 |
4.28 |
5.41 |
5.88 |
5.90 |
5.75 |
5.13 |
4.44 |
3.80 |
2.83 |
2.39 |
Upright - 0° |
3.33 |
3.19 |
3.26 |
2.85 |
2.37 |
2.18 |
2.23 |
2.46 |
2.93 |
3.67 |
3.59 |
3.49 |
56° angle Year-round tilt |
3.67 |
4.03 |
4.89 |
5.47 |
5.40 |
5.23 |
5.18 |
4.95 |
4.81 |
4.80 |
4.05 |
3.67 |
40° angle Best winter tilt |
3.87 |
4.09 |
4.76 |
5.05 |
4.77 |
4.53 |
4.53 |
4.49 |
4.58 |
4.83 |
4.25 |
3.93 |
72° angle Best summer tilt |
3.27 |
3.76 |
4.77 |
5.62 |
5.79 |
5.70 |
5.60 |
5.19 |
4.79 |
4.50 |
3.64 |
3.22 |
Tilt adjusted each month |
3.87 40° |
4.09 48° |
4.89 56° |
5.62 64° |
5.79 72° |
5.90 80° |
5.60 72° |
5.21 64° |
4.81 56° |
4.85 48° |
4.25 40° |
3.97 32° |
South Dakota
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.75 |
2.54 |
3.61 |
4.79 |
5.83 |
6.51 |
6.60 |
5.75 |
4.42 |
3.04 |
1.93 |
1.47 |
Upright - 0° |
3.44 |
3.52 |
3.48 |
3.16 |
2.91 |
2.84 |
2.99 |
3.33 |
3.77 |
3.91 |
3.40 |
3.04 |
46° angle Year-round tilt |
3.45 |
3.98 |
4.58 |
5.02 |
5.41 |
5.62 |
5.85 |
5.76 |
5.33 |
4.57 |
3.53 |
3.01 |
30° angle Best winter tilt |
3.68 |
4.07 |
4.45 |
4.60 |
4.73 |
4.80 |
5.03 |
5.17 |
5.08 |
4.62 |
3.71 |
3.21 |
62° angle Best summer tilt |
3.03 |
3.67 |
4.47 |
5.19 |
5.83 |
6.19 |
6.39 |
6.06 |
5.28 |
4.27 |
3.14 |
2.62 |
Tilt adjusted each month |
3.68 30° |
4.07 38° |
4.58 46° |
5.19 54° |
5.83 62° |
6.54 70° |
6.39 62° |
6.09 54° |
5.33 46° |
4.63 38° |
3.71 30° |
3.25 22° |
Tennessee
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.06 |
2.72 |
3.83 |
4.97 |
5.47 |
5.79 |
5.79 |
5.30 |
4.63 |
3.62 |
2.43 |
1.88 |
Upright - 0° |
2.72 |
2.81 |
3.00 |
2.77 |
2.38 |
2.26 |
2.33 |
2.63 |
3.23 |
3.69 |
3.13 |
2.69 |
54° angle Year-round tilt |
3.00 |
3.51 |
4.38 |
5.02 |
5.04 |
5.13 |
5.22 |
5.14 |
5.13 |
4.70 |
3.52 |
2.87 |
38° angle Best winter tilt |
3.14 |
3.54 |
4.25 |
4.63 |
4.46 |
4.45 |
4.55 |
4.65 |
4.90 |
4.74 |
3.67 |
3.03 |
70° angle Best summer tilt |
2.71 |
3.29 |
4.30 |
5.17 |
5.40 |
5.58 |
5.64 |
5.39 |
5.10 |
4.41 |
3.18 |
2.55 |
Tilt adjusted each month |
3.14 38° |
3.55 46° |
4.38 54° |
5.18 62° |
5.40 70° |
5.79 78° |
5.64 70° |
5.42 62° |
5.13 54° |
4.76 46° |
3.67 38° |
3.05 30° |
Texas
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.83 |
3.41 |
4.40 |
5.25 |
5.62 |
6.36 |
6.56 |
5.94 |
4.97 |
4.05 |
3.07 |
2.63 |
Upright - 0° |
3.35 |
3.21 |
3.07 |
2.57 |
2.16 |
2.05 |
2.14 |
2.50 |
3.03 |
3.55 |
3.45 |
3.35 |
60° angle Year-round tilt |
3.82 |
4.18 |
4.86 |
5.27 |
5.19 |
5.65 |
5.90 |
5.72 |
5.31 |
4.87 |
4.07 |
3.67 |
44° angle Best winter tilt |
4.03 |
4.25 |
4.74 |
4.89 |
4.61 |
4.88 |
5.12 |
5.18 |
5.08 |
4.90 |
4.25 |
3.91 |
76° angle Best summer tilt |
3.41 |
3.89 |
4.75 |
5.39 |
5.54 |
6.15 |
6.38 |
5.98 |
5.27 |
4.57 |
3.66 |
3.24 |
Tilt adjusted each month |
4.03 44° |
4.25 52° |
4.86 60° |
5.39 68° |
5.54 76° |
6.36 84° |
6.38 76° |
6.00 68° |
5.31 60° |
4.92 52° |
4.25 44° |
3.95 36° |
Utah
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.31 |
3.11 |
4.47 |
5.54 |
6.55 |
7.31 |
7.08 |
6.11 |
5.10 |
3.76 |
2.45 |
2.07 |
Upright - 0° |
4.10 |
3.99 |
4.10 |
3.36 |
2.91 |
2.73 |
2.83 |
3.21 |
4.03 |
4.53 |
3.92 |
4.07 |
50° angle Year-round tilt |
4.17 |
4.62 |
5.61 |
5.76 |
6.04 |
6.38 |
6.33 |
6.04 |
6.01 |
5.43 |
4.14 |
3.99 |
34° angle Best winter tilt |
4.46 |
4.74 |
5.49 |
5.30 |
5.27 |
5.41 |
5.43 |
5.43 |
5.76 |
5.52 |
4.37 |
4.32 |
66° angle Best summer tilt |
3.64 |
4.24 |
5.42 |
5.93 |
6.51 |
7.03 |
6.91 |
6.34 |
5.93 |
5.03 |
3.67 |
3.43 |
Tilt adjusted each month |
4.46 34° |
4.74 42° |
5.61 50° |
5.93 58° |
6.51 66° |
7.34 74° |
6.91 66° |
6.37 58° |
6.01 50° |
5.53 42° |
4.37 34° |
4.39 26° |
Vermont
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.61 |
2.53 |
3.54 |
4.34 |
4.86 |
5.43 |
5.49 |
4.81 |
3.72 |
2.45 |
1.50 |
1.26 |
Upright - 0° |
3.06 |
3.55 |
3.42 |
2.87 |
2.53 |
2.54 |
2.65 |
2.84 |
3.06 |
2.85 |
2.30 |
2.38 |
46° angle Year-round tilt |
3.08 |
4.00 |
4.49 |
4.51 |
4.50 |
4.72 |
4.89 |
4.77 |
4.33 |
3.41 |
2.46 |
2.40 |
30° angle Best winter tilt |
3.27 |
4.09 |
4.37 |
4.14 |
3.97 |
4.08 |
4.26 |
4.30 |
4.11 |
3.41 |
2.55 |
2.54 |
62° angle Best summer tilt |
2.72 |
3.68 |
4.38 |
4.66 |
4.84 |
5.17 |
5.31 |
5.02 |
4.32 |
3.24 |
2.24 |
2.11 |
Tilt adjusted each month |
3.27 30° |
4.09 38° |
4.49 46° |
4.67 54° |
4.84 62° |
5.45 70° |
5.31 62° |
5.05 54° |
4.33 46° |
3.43 38° |
2.55 30° |
2.56 22° |
Virginia
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.17 |
2.83 |
3.89 |
4.76 |
5.38 |
5.63 |
5.56 |
4.98 |
4.28 |
3.58 |
2.43 |
1.94 |
Upright - 0° |
3.11 |
3.10 |
3.15 |
2.73 |
2.42 |
2.28 |
2.34 |
2.56 |
3.04 |
3.79 |
3.32 |
3.00 |
53° angle Year-round tilt |
3.34 |
3.79 |
4.53 |
4.82 |
4.97 |
5.00 |
5.02 |
4.83 |
4.74 |
4.75 |
3.65 |
3.12 |
37° angle Best winter tilt |
3.52 |
3.84 |
4.40 |
4.44 |
4.39 |
4.34 |
4.39 |
4.38 |
4.52 |
4.79 |
3.82 |
3.32 |
69° angle Best summer tilt |
2.98 |
3.53 |
4.43 |
4.97 |
5.31 |
5.44 |
5.42 |
5.07 |
4.72 |
4.44 |
3.28 |
2.74 |
Tilt adjusted each month |
3.52 37° |
3.85 45° |
4.53 53° |
4.97 61° |
5.31 69° |
5.64 76° |
5.42 69° |
5.09 61° |
4.74 53° |
4.81 45° |
3.82 37° |
3.35 30° |
Washington
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.06 |
1.93 |
2.94 |
4.05 |
4.99 |
5.51 |
5.88 |
5.20 |
3.98 |
2.25 |
1.25 |
0.91 |
Upright - 0° |
1.55 |
2.42 |
2.69 |
2.76 |
2.73 |
2.72 |
2.97 |
3.23 |
3.42 |
2.62 |
1.79 |
1.43 |
43° angle Year-round tilt |
1.68 |
2.79 |
3.52 |
4.15 |
4.55 |
4.76 |
5.21 |
5.18 |
4.68 |
3.13 |
1.95 |
1.51 |
27° angle Best winter tilt |
1.72 |
2.79 |
3.37 |
3.80 |
4.01 |
4.10 |
4.51 |
4.65 |
4.43 |
3.10 |
1.99 |
1.56 |
59° angle Best summer tilt |
1.56 |
2.65 |
3.50 |
4.33 |
4.91 |
5.24 |
5.68 |
5.47 |
4.70 |
3.00 |
1.82 |
1.39 |
Tilt adjusted each month |
1.72 27° |
2.81 35° |
3.532 43° |
4.34 51° |
4.91 59° |
5.55 66° |
5.68 59° |
5.51 51° |
4.68 43° |
3.14 35° |
1.99 27° |
1.56 20° |
West Virginia
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.85 |
2.49 |
3.51 |
4.58 |
5.09 |
5.82 |
5.63 |
4.99 |
4.31 |
3.33 |
2.12 |
1.65 |
Upright - 0° |
2.56 |
2.66 |
2.84 |
2.68 |
2.37 |
2.36 |
2.39 |
2.61 |
3.14 |
3.53 |
2.81 |
2.46 |
52° angle Year-round tilt |
2.79 |
3.27 |
4.05 |
4.64 |
4.70 |
5.15 |
5.07 |
4.85 |
4.82 |
4.42 |
3.13 |
2.59 |
36° angle Best winter tilt |
2.91 |
3.29 |
3.92 |
4.27 |
4.16 |
4.45 |
4.43 |
4.39 |
4.59 |
4.44 |
3.25 |
2.74 |
68° angle Best summer tilt |
2.51 |
3.07 |
3.98 |
4.79 |
5.03 |
5.62 |
5.49 |
5.09 |
4.80 |
4.15 |
2.84 |
2.31 |
Tilt adjusted each month |
2.91 36° |
3.30 44° |
4.05 52° |
4.79 60° |
5.03 68° |
5.83 76° |
5.49 68° |
5.12 60° |
4.82 52° |
4.46 44° |
3.25 36° |
2.75 28° |
Wisconsin
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
1.80 |
2.67 |
3.58 |
4.49 |
5.33 |
5.97 |
5.87 |
5.05 |
4.01 |
2.76 |
1.79 |
1.52 |
Upright - 0° |
3.34 |
3.63 |
3.34 |
2.89 |
2.67 |
2.63 |
2.71 |
2.89 |
3.25 |
3.23 |
2.82 |
3.05 |
47° angle Year-round tilt |
3.39 |
4.13 |
4.45 |
4.64 |
4.92 |
5.18 |
5.24 |
4.99 |
4.67 |
3.87 |
3.00 |
3.01 |
31° angle Best winter tilt |
3.60 |
4.22 |
4.32 |
4.25 |
4.33 |
4.45 |
4.54 |
4.49 |
4.44 |
3.88 |
3.12 |
3.22 |
63° angle Best summer tilt |
2.98 |
3.81 |
4.35 |
4.80 |
5.30 |
5.67 |
5.71 |
5.25 |
4.66 |
3.65 |
2.70 |
2.61 |
Tilt adjusted each month |
3.60 31° |
4.22 39° |
4.45 47° |
4.80 55° |
5.30 63° |
5.99 70° |
5.71 63° |
5.29 55° |
4.67 47° |
3.90 39° |
3.12 31° |
3.26 24° |
Wyoming
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec |
|
Flat - 90° |
2.13 |
2.92 |
4.10 |
5.13 |
6.14 |
6.92 |
6.65 |
5.82 |
4.79 |
3.52 |
2.34 |
1.89 |
Upright - 0° |
3.81 |
3.78 |
3.76 |
3.18 |
2.84 |
2.73 |
2.80 |
3.15 |
3.83 |
4.28 |
3.83 |
3.76 |
49° angle Year-round tilt |
3.88 |
4.37 |
5.12 |
5.32 |
5.66 |
5.98 |
5.96 |
5.76 |
5.65 |
5.11 |
4.03 |
3.69 |
33° angle Best winter tilt |
4.13 |
4.47 |
4.99 |
4.89 |
4.96 |
5.09 |
5.13 |
5.18 |
5.40 |
5.18 |
4.25 |
3.99 |
65° angle Best summer tilt |
3.39 |
4.02 |
4.97 |
5.49 |
6.10 |
6.58 |
6.50 |
6.05 |
5.59 |
4.75 |
3.58 |
3.18 |
Tilt adjusted each month |
4.13 33° |
4.47 41° |
5.12 49° |
5.49 57° |
6.10 65° |
6.93 72° |
6.50 65° |
6.08 57° |
5.65 49° |
5.19 41° |
4.25 33° |
4.05 26° |