Solar Insolation Map for Photovoltaics: Determining Your Peak Sun Hours
Find the nearest city near you to determine your yearly average sun hours. When calculating the size of your system, it is important to use the yearly average so that you can account for how much solar energy you could produce based on the amount of sunlight you receive throughout the year.
| State, City | Summer Avg. | Winter Avg. | Year Avg. |
|---|---|---|---|
| AL, Montgomery | 4.69 | 3.37 | 4.23 |
| AK, Bethel | 6.29 | 2.37 | 3.81 |
| AK, Fairbanks | 5.87 | 2.12 | 3.99 |
| AK, Mantanuska | 5.24 | 1.74 | 3.55 |
| AZ, Page | 7.3 | 5.65 | 6.36 |
| AZ, Phoenix | 7.13 | 5.78 | 6.58 |
| AZ, Tucson | 7.42 | 6.01 | 6.57 |
| AR, Little Rock | 5.29 | 3.88 | 4.69 |
| CA, Davis | 6.09 | 3.31 | 5.1 |
| CA, Fresno | 6.19 | 3.42 | 5.38 |
| CA, Inyokem | 8.7 | 6.97 | 7.66 |
| CA, La Jolla | 5.24 | 4.29 | 4.77 |
| CA, Los Angeles | 6.14 | 5.03 | 5.62 |
| CA, Riverside | 6.35 | 5.35 | 5.87 |
| CA, Santa Maria | 6.52 | 5.42 | 5.94 |
| CA, Soda Springs | 6.47 | 4.4 | 5.6 |
| CO, Boulder | 5.72 | 4.44 | 4.87 |
| CO, Granby | 7.47 | 5.15 | 5.69 |
| CO, Grand Junction | 6.34 | 5.23 | 5.86 |
| CO, Grand Lake | 5.86 | 3.56 | 5.08 |
| D.C. Washington | 4.69 | 3.37 | 4.23 |
| FL, Apalachicola | 5.98 | 4.92 | 5.49 |
| FL, Belle Island | 5.31 | 4.58 | 4.99 |
| FL, Gainesville | 5.81 | 4.71 | 5.27 |
| FL, Miami | 6.26 | 5.05 | 5.62 |
| FL, Tampa | 6.16 | 5.26 | 5.67 |
| GA, Atlanta | 5.16 | 4.09 | 4.74 |
| GA, Griffin | 5.41 | 4.26 | 4.99 |
| HI, Honolulu | 6.71 | 5.59 | 6.02 |
| IA, Ames | 4.8 | 3.73 | 4.4 |
| ID, Boise | 5.83 | 3.33 | 4.92 |
| IL, Chicago | 4.08 | 1.47 | 3.14 |
| IN, Indianapolis | 5.02 | 2.55 | 4.21 |
| KS, Dodge City | 4.14 | 5.28 | 5.79 |
| KS, Manhattan | 5.08 | 3.62 | 4.57 |
| KY, Lexington | 5.97 | 3.6 | 4.94 |
| LA, Lake Charles | 5.73 | 4.29 | 4.93 |
| LA, New Orleans | 5.71 | 3.63 | 4.92 |
| LA, Shreveport | 4.99 | 3.87 | 4.63 |
| MA, Blue Hill | 4.38 | 3.33 | 4.05 |
| MA, Boston | 4.27 | 2.99 | 3.84 |
| MA, E. Wareham | 4.48 | 3.06 | 3.99 |
| MA, Lynn | 4.6 | 2.33 | 3.79 |
| MA, Natick | 4.62 | 3.09 | 4.1 |
| MD, Silver Hill | 4.71 | 3.84 | 4.47 |
| ME, Caribou | 5.62 | 2.57 | 4.19 |
| ME, Portland | 5.2 | 3.56 | 4.51 |
| MI, E. Lansing | 4.71 | 2.7 | 4 |
| MI, Sault Ste. Marie | 4.83 | 2.33 | 4.2 |
| MN, St. Cloud | 5.43 | 3.53 | 4.53 |
| MO, Columbia | 5.5 | 3.97 | 4.73 |
| MO, St. Louis | 4.87 | 3.24 | 3.78 |
| MS, Meridian | 4.86 | 3.64 | 4.44 |
| MT, Glasgow | 5.97 | 4.09 | 5.15 |
| MT, Great Falls | 5.7 | 3.66 | 4.93 |
| MT, Summit | 5.17 | 2.39 | 3.99 |
| NC, Cape Hatteras | 5.81 | 4.69 | 5.31 |
| NC, Greensboro | 5.05 | 4 | 4.71 |
| ND, Bismark | 5.48 | 3.97 | 5.01 |
| NE, Lincoln | 5.4 | 4.38 | 4.79 |
| NE, North Omaha | 5.28 | 4.26 | 4.9 |
| NJ, Sea Brook | 4.76 | 3.2 | 4.21 |
| NM, Albuquerque | 7.16 | 6.21 | 6.77 |
| NV, Ely | 6.48 | 5.49 | 5.98 |
| NV, Las Vegas | 7.13 | 5.83 | 6.41 |
| NY, Bridge Hampton | 3.93 | 1.62 | 3.16 |
| NY, Ithaca | 4.57 | 2.29 | 3.79 |
| NY, New York | 4.97 | 3.03 | 4.08 |
| NY, Rochester | 4.22 | 1.58 | 3.31 |
| NY, Schenectady | 3.92 | 2.53 | 3.55 |
| OH, Cleveland | 4.79 | 2.69 | 3.94 |
| OH, Columbus | 5.26 | 2.66 | 4.16 |
| OK, Oklahoma City | 6.26 | 4.98 | 5.59 |
| OK, Stillwater | 5.52 | 4.22 | 4.99 |
| OR, Astoria | 4.76 | 1.99 | 3.72 |
| OR, Corvallis | 5.71 | 1.9 | 4.03 |
| OR, Medford | 5.84 | 2.02 | 4.51 |
| PA, Pittsburgh | 4.19 | 1.45 | 3.28 |
| PA, State College | 4.44 | 2.78 | 3.91 |
| RI, Newport | 4.69 | 3.58 | 4.23 |
| SC, Charleston | 5.72 | 4.23 | 5.06 |
| SD, Rapid City | 5.91 | 4.56 | 5.23 |
| TN, Nashville | 5.2 | 3.14 | 4.45 |
| TN, Oak Ridge | 5.06 | 3.22 | 4.37 |
| TX, Brownsville | 5.49 | 4.42 | 4.92 |
| TX, El Paso | 7.42 | 5.87 | 6.72 |
| TX, Fort Worth | 6 | 4.8 | 5.83 |
| TX, Midland | 6.33 | 5.23 | 5.83 |
| TX, San Antonio | 5.88 | 4.65 | 5.3 |
| UT, Flaming Gorge | 6.63 | 5.48 | 5.83 |
| UT, Salt Lake City | 6.09 | 3.78 | 5.26 |
| VA, Richmond | 4.5 | 3.37 | 4.13 |
| WA, Prosser | 6.21 | 3.06 | 5.03 |
| WA, Pullman | 6.07 | 2.9 | 4.73 |
| WA, Richland | 6.13 | 2.01 | 4.43 |
| WA, Seattle | 4.83 | 1.6 | 3.57 |
| WA, Spokane | 5.53 | 1.16 | 4.48 |
| WV, Charleston | 4.12 | 2.47 | 3.65 |
| WI, Madison | 4.85 | 3.28 | 4.29 |
| WY, Lander | 6.81 | 5.5 | 6.06 |
| Province, City | Summer Avg. | Winter Avg. | Year Avg |
|---|---|---|---|
| Alberta, Edmonton | 4.95 | 2.13 | 3.75 |
| Alberta, Suffield | 5.19 | 2.75 | 4.1 |
| British Columbia, Kamloops | 4.48 | 1.46 | 3.29 |
| British Columbia, Prince George | 4.13 | 1.33 | 3.14 |
| British Columbia, Vancouver | 4.23 | 1.33 | 3.14 |
| Manitoba, The Pas | 5.02 | 2.02 | 3.56 |
| Manitoba, Winnipeg New Brunswick | 5.2 | 2.77 | 4.02 |
| Fredericton | 4.23 | 2.54 | 3.56 |
| Newfoundland, Goose Bay | 4.65 | 2.02 | 3.33 |
| Newfoundland, St. Johns | 3.89 | 1.83 | 3.15 |
| Northwest Territory, Fort Smith | 5.16 | 0.88 | 3.29 |
| Northwest Territory, Norman Wells | 5.04 | 0.06 | 2.89 |
| Nova Scotia, Halifax | 4.02 | 2.16 | 3.38 |
| Ontario, Ottawa | 4.63 | 2.35 | 3.7 |
| Ontario, Toronto | 3.98 | 2.13 | 3.44 |
| Prince Edward Island, Charlottetown | 4.31 | 2.29 | 3.56 |
| Quebec, Montreal | 4.2 | 2.29 | 3.56 |
| Quebec, Sept-Isles | 4.29 | 2.33 | 3.5 |
| Saskatchewan, Swift Current | 5.25 | 2.77 | 4.23 |
| Yukon, Whitehorse | 4.81 | 0.69 | 3.1 |
Source: NREL
For more in depth information about solar radiation around the world, visit the National Renewable Energy Laboratory’s NSRDB (National Solar Radiation Database)