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Annual/Monthly City Insolation Values

(10 year average) kWh/m2/day

CityYear AvgJanFebMarAprMayJunJulAugSepOctNovDec
Albuquerque4.972.923.974.926.36.686.946.665.85.684.183.162.5
Anchorage2.090.210.761.683.123.984.584.253.161.980.980.370.12
Annapolis3.981.962.83.714.555.546.035.775.344.483.42.371.81
Atlanta4.372.313.374.085.26.026.015.815.594.763.952.982.33
Billings3.961.552.573.524.825.636.456.395.754.673.191.771.3
Birmingham4.342.293.314.045.145.925.985.815.74.83.932.962.25
Boise4.241.732.723.775.225.96.577.176.125.283.291.741.46
Boston3.581.662.53.514.135.115.475.445.054.122.841.741.4
Casper4.251.932.83.795.135.96.686.55.95.133.592.061.65
Charleston3.731.752.643.344.265.25.675.495.194.263.192.151.62
Charlotte4.22.223.173.954.985.86.015.765.274.583.752.762.21
Chicago3.721.52.453.24.485.566.075.685.274.513.071.691.26
Columbia4.152.142.913.625.035.566.226.135.644.953.572.251.82
Columbus3.831.642.573.264.635.46.085.735.294.743.291.961.45
Denver4.552.253.24.325.616.116.716.55.865.474.012.591.98
Detroit3.581.432.333.194.345.445.985.644.994.252.731.521.14
Dover3.841.852.623.64.335.445.915.645.34.383.232.211.66
Dubuque3.771.642.583.344.575.546.065.815.264.333.031.721.35
Fargo3.681.442.393.364.795.625.825.945.144.012.831.591.31
Great Falls3.791.32.363.414.845.566.186.445.534.42.91.531.11
Hartford3.591.72.433.484.075.145.585.385.044.132.911.811.42
Honolulu5.964.385.155.996.697.057.487.377.076.515.464.414.01
Houston4.722.473.54.45.596.036.456.366.075.464.613.32.44
Indianapolis3.871.672.593.284.675.466.115.795.374.763.331.971.46
Jackson3.591.472.413.224.335.465.935.574.994.32.781.551.17
Kansas City4.112.062.893.624.925.586.176.215.594.93.492.21.75
Las Vegas5.33.024.135.056.577.257.697.376.426.084.263.182.6
Little Rock4.462.363.394.015.325.716.196.155.855.254.172.952.25
Los Angeles5.43.094.255.096.587.297.627.456.726.114.423.432.72
Louisville3.91.712.653.324.735.386.085.795.354.83.422.11.56
Manchester3.581.662.53.514.135.115.475.445.054.122.841.741.4
Miami5.263.724.615.426.46.616.296.266.085.474.843.963.46
Milwaukee3.691.432.413.294.485.66.095.745.214.342.91.61.2
Minneapolis3.681.62.613.34.555.445.865.775.124.122.91.621.34
Montpelier3.431.582.543.54.0555.245.374.923.792.461.521.28
Nashville4.041.942.93.544.765.575.95.865.624.633.532.451.82
New Orleans4.762.643.734.675.86.66.156.095.75.134.483.492.68
New York3.531.672.373.413.935.115.485.265.014.052.851.821.4
Omaha3.981.922.763.454.745.66.146.115.464.743.3421.57
Philadelphia3.841.852.623.64.335.445.915.645.34.383.232.211.66
Phoenix5.383.254.415.176.767.427.76.996.116.024.443.522.75
Pittsburgh3.531.592.43.264.075.055.535.274.944.052.881.861.41
Portland3.821.382.333.494.575.466.096.645.784.82.791.411.1
Portland3.821.382.333.494.575.466.096.645.784.82.791.411.1
Providence3.641.72.463.534.25.175.675.485.084.212.971.81.43
Salt Lake City4.532.233.154.095.576.266.986.865.985.393.682.291.97
San Antonio4.832.573.74.435.545.946.626.496.285.74.673.432.62
San Francisco4.892.353.334.425.956.847.397.556.515.753.922.652.06
Seattle3.531.142.043.234.265.195.756.275.464.432.51.210.9
Sioux Falls3.871.722.713.314.655.616.16.045.424.473.21.781.43
St. Louis4.092.022.823.524.975.566.216.055.634.913.552.211.73
Trenton3.631.712.393.434.045.265.675.395.144.1831.981.48
Tulsa4.362.333.223.95.255.586.326.45.85.083.82.622.06
Washington3.91.952.83.664.465.425.885.635.224.383.362.341.79
Data courtesy ofNASA – Surface meteorology and Solar Energy Data Set
Reference:
Whitlock, C. E., et al., Release 3 NASA Surface Meteorology and Solar Energy Data Set for Renewable Energy Industry Use.
Rise & Shine 2000, the 26th Annual Conference of the Solar Energy Society of Canada Inc. and Solar, Oct. 21-24, 2000,
Halifax, Nova Scotia, Canada.