Peak sun hours by state, every month
How many peak sun hours a south-facing panel gets in each state, month by month, and what that means in watt-hours from your panels. From NREL's PVWatts v8 for the largest city in each state.
Last updatedOct 18, 2026
Sun hoursNREL (now NLR) PVWatts v8.5.0, requested Oct 18, 2026
Places51: the largest city in each state and DC
Result
0sun hours
Next: see how fast these panels refill a station, or compare solar with wall and car charging.
All states, every month
Peak sun hours a day (kWh per square meter per day) on a fixed panel facing south and tilted at the city's latitude. Each state's lowest month is shaded. Download as CSV.
| State | Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AlabamaBirmingham, tilt 34° | 5.15 | 3.80 | 4.14 | 5.26 | 5.89 | 6.02 | 5.77 | 5.74 | 5.78 | 5.56 | 5.46 | 4.67 | 3.71 |
| AlaskaAnchorage, tilt 61° | 3.03 | 0.76 | 1.78 | 4.23 | 4.51 | 4.81 | 4.79 | 4.34 | 4.30 | 3.50 | 1.91 | 0.89 | 0.55 |
| ArizonaPhoenix, tilt 33° | 6.57 | 5.49 | 6.04 | 6.81 | 7.49 | 7.41 | 7.38 | 6.65 | 6.75 | 6.94 | 6.49 | 5.97 | 5.43 |
| ArkansasLittle Rock, tilt 35° | 5.11 | 4.08 | 4.63 | 4.45 | 5.24 | 5.32 | 6.04 | 5.93 | 5.82 | 5.96 | 5.38 | 4.71 | 3.71 |
| CaliforniaLos Angeles, tilt 34° | 6.09 | 5.02 | 5.41 | 6.03 | 6.61 | 6.04 | 6.61 | 6.87 | 7.24 | 6.89 | 6.14 | 5.60 | 4.61 |
| ColoradoDenver, tilt 40° | 5.73 | 4.65 | 5.51 | 6.12 | 6.16 | 5.92 | 6.29 | 6.16 | 6.15 | 6.35 | 5.64 | 5.29 | 4.57 |
| ConnecticutBridgeport, tilt 41° | 4.73 | 3.61 | 4.41 | 5.01 | 4.90 | 5.42 | 5.57 | 5.70 | 5.44 | 5.49 | 4.48 | 3.67 | 3.08 |
| DelawareWilmington, tilt 40° | 4.78 | 3.51 | 4.34 | 5.12 | 5.39 | 5.25 | 5.30 | 5.61 | 5.57 | 5.34 | 4.43 | 4.30 | 3.23 |
| District of ColumbiaWashington, tilt 39° | 4.79 | 3.73 | 4.03 | 5.19 | 5.64 | 5.06 | 5.55 | 5.61 | 5.37 | 5.14 | 4.79 | 3.99 | 3.41 |
| FloridaJacksonville, tilt 30° | 5.44 | 4.83 | 5.00 | 5.99 | 6.28 | 6.15 | 5.46 | 5.67 | 5.76 | 5.40 | 5.36 | 5.09 | 4.23 |
| GeorgiaAtlanta, tilt 34° | 5.08 | 4.07 | 4.54 | 4.92 | 5.68 | 5.80 | 5.45 | 5.57 | 5.56 | 5.53 | 5.44 | 4.58 | 3.87 |
| HawaiiHonolulu, tilt 21° | 5.77 | 5.28 | 5.28 | 5.82 | 5.93 | 6.02 | 6.18 | 6.28 | 6.33 | 6.50 | 5.67 | 5.03 | 4.89 |
| IdahoBoise, tilt 44° | 5.15 | 2.55 | 3.97 | 5.03 | 6.02 | 6.17 | 6.58 | 7.07 | 7.07 | 6.39 | 5.05 | 3.33 | 2.61 |
| IllinoisChicago, tilt 42° | 4.46 | 2.96 | 4.01 | 4.34 | 4.98 | 5.08 | 5.43 | 5.92 | 5.50 | 5.21 | 4.12 | 3.25 | 2.66 |
| IndianaIndianapolis, tilt 40° | 4.64 | 3.42 | 4.00 | 4.35 | 5.17 | 4.89 | 5.64 | 5.60 | 5.89 | 5.50 | 4.58 | 3.64 | 2.97 |
| IowaDes Moines, tilt 42° | 4.78 | 3.55 | 4.40 | 4.90 | 5.22 | 5.15 | 5.65 | 6.05 | 5.46 | 5.33 | 4.45 | 3.82 | 3.34 |
| KansasWichita, tilt 38° | 5.40 | 4.30 | 5.31 | 5.54 | 5.73 | 5.67 | 6.16 | 6.20 | 6.32 | 5.76 | 5.18 | 4.68 | 3.95 |
| KentuckyLouisville, tilt 38° | 4.80 | 3.55 | 3.93 | 4.53 | 5.12 | 5.34 | 5.73 | 5.58 | 5.85 | 5.81 | 4.87 | 4.03 | 3.29 |
| LouisianaNew Orleans, tilt 30° | 5.27 | 4.00 | 4.54 | 5.57 | 5.83 | 6.03 | 5.60 | 5.35 | 5.36 | 5.85 | 5.91 | 5.07 | 4.14 |
| MainePortland, tilt 44° | 4.57 | 3.77 | 4.65 | 5.30 | 4.91 | 5.10 | 5.09 | 5.29 | 5.25 | 5.32 | 4.01 | 3.25 | 2.92 |
| MarylandBaltimore, tilt 39° | 4.88 | 4.04 | 4.72 | 5.01 | 5.35 | 5.35 | 5.50 | 5.80 | 5.56 | 5.16 | 4.64 | 3.97 | 3.50 |
| MassachusettsBoston, tilt 42° | 4.72 | 3.91 | 4.55 | 5.29 | 5.16 | 5.42 | 5.05 | 5.67 | 5.48 | 5.37 | 4.44 | 3.46 | 2.82 |
| MichiganDetroit, tilt 42° | 4.42 | 2.94 | 4.02 | 4.38 | 5.04 | 5.18 | 5.46 | 5.75 | 5.52 | 5.26 | 4.06 | 3.12 | 2.36 |
| MinnesotaMinneapolis, tilt 45° | 4.66 | 3.66 | 4.63 | 5.61 | 5.21 | 4.87 | 5.26 | 5.89 | 5.49 | 5.28 | 4.03 | 3.21 | 2.75 |
| MississippiJackson, tilt 32° | 5.21 | 4.28 | 4.23 | 5.32 | 5.74 | 5.82 | 5.89 | 5.76 | 5.72 | 5.97 | 5.56 | 4.69 | 3.51 |
| MissouriKansas City, tilt 39° | 5.05 | 3.86 | 4.62 | 4.70 | 5.40 | 5.49 | 5.70 | 5.89 | 5.83 | 5.76 | 5.16 | 4.42 | 3.72 |
| MontanaBillings, tilt 46° | 4.80 | 3.16 | 3.97 | 4.90 | 5.00 | 5.41 | 5.83 | 6.48 | 6.34 | 5.69 | 4.71 | 3.32 | 2.78 |
| NebraskaOmaha, tilt 41° | 5.03 | 3.83 | 4.82 | 5.13 | 5.21 | 5.16 | 5.98 | 6.04 | 5.65 | 5.85 | 5.14 | 4.20 | 3.32 |
| NevadaLas Vegas, tilt 36° | 6.47 | 5.17 | 5.90 | 6.62 | 7.20 | 7.23 | 7.33 | 6.68 | 6.97 | 7.30 | 6.62 | 5.60 | 4.98 |
| New HampshireManchester, tilt 43° | 4.65 | 3.72 | 4.81 | 5.42 | 5.16 | 5.03 | 4.91 | 5.43 | 5.29 | 5.16 | 4.07 | 3.58 | 3.17 |
| New JerseyNewark, tilt 41° | 4.65 | 3.39 | 4.44 | 4.77 | 4.78 | 5.14 | 5.48 | 5.47 | 5.60 | 5.21 | 4.65 | 3.67 | 3.17 |
| New MexicoAlbuquerque, tilt 35° | 6.48 | 5.50 | 6.13 | 6.85 | 7.19 | 7.09 | 7.24 | 6.71 | 6.68 | 6.91 | 6.51 | 5.88 | 5.12 |
| New YorkNew York City, tilt 41° | 4.45 | 3.57 | 4.33 | 4.52 | 4.91 | 5.03 | 5.25 | 5.38 | 5.19 | 5.04 | 4.04 | 3.27 | 2.88 |
| North CarolinaCharlotte, tilt 35° | 5.20 | 4.19 | 4.82 | 5.08 | 5.62 | 5.90 | 5.71 | 5.82 | 5.85 | 5.74 | 4.99 | 4.78 | 3.88 |
| North DakotaFargo, tilt 47° | 4.47 | 3.06 | 3.91 | 4.98 | 5.43 | 4.83 | 5.38 | 5.99 | 5.76 | 4.66 | 4.10 | 2.99 | 2.56 |
| OhioColumbus, tilt 40° | 4.53 | 3.21 | 3.61 | 4.17 | 5.13 | 5.30 | 5.58 | 5.58 | 5.38 | 5.52 | 4.46 | 3.68 | 2.76 |
| OklahomaOklahoma City, tilt 35° | 5.45 | 4.38 | 4.60 | 5.19 | 6.19 | 5.43 | 6.13 | 6.22 | 6.54 | 5.88 | 5.51 | 4.83 | 4.44 |
| OregonPortland, tilt 46° | 3.97 | 1.64 | 3.29 | 3.67 | 4.70 | 4.93 | 5.00 | 6.08 | 5.66 | 5.29 | 3.56 | 2.23 | 1.61 |
| PennsylvaniaPhiladelphia, tilt 40° | 4.81 | 3.63 | 4.83 | 5.17 | 5.50 | 5.18 | 5.44 | 5.66 | 5.56 | 5.03 | 4.69 | 3.71 | 3.31 |
| Rhode IslandProvidence, tilt 42° | 4.72 | 4.01 | 4.37 | 5.03 | 5.31 | 5.24 | 5.15 | 5.51 | 5.42 | 5.31 | 4.48 | 3.52 | 3.23 |
| South CarolinaCharleston, tilt 33° | 5.28 | 4.54 | 5.19 | 5.41 | 5.75 | 6.03 | 5.74 | 5.69 | 5.39 | 5.45 | 5.37 | 4.95 | 3.88 |
| South DakotaSioux Falls, tilt 44° | 4.98 | 3.85 | 4.35 | 5.29 | 5.41 | 5.02 | 5.89 | 6.43 | 5.84 | 5.50 | 4.70 | 4.08 | 3.36 |
| TennesseeNashville, tilt 36° | 4.77 | 3.33 | 3.97 | 4.59 | 5.09 | 5.46 | 5.41 | 5.56 | 5.59 | 5.53 | 4.95 | 4.28 | 3.52 |
| TexasHouston, tilt 30° | 5.15 | 4.05 | 4.17 | 5.44 | 5.40 | 5.64 | 5.71 | 5.83 | 5.75 | 5.58 | 5.47 | 5.02 | 3.76 |
| UtahSalt Lake City, tilt 41° | 5.38 | 3.52 | 4.65 | 5.40 | 5.56 | 6.19 | 6.71 | 6.72 | 6.79 | 6.27 | 5.52 | 4.06 | 3.11 |
| VermontBurlington, tilt 44° | 4.38 | 3.06 | 4.25 | 5.22 | 4.89 | 5.31 | 4.99 | 5.33 | 5.42 | 5.28 | 3.60 | 2.77 | 2.36 |
| VirginiaVirginia Beach, tilt 37° | 4.97 | 3.92 | 4.54 | 4.94 | 5.61 | 5.64 | 5.71 | 5.73 | 5.58 | 5.05 | 5.07 | 4.35 | 3.52 |
| WashingtonSeattle, tilt 48° | 3.82 | 1.96 | 2.83 | 3.48 | 4.75 | 5.19 | 4.96 | 5.42 | 5.88 | 4.71 | 3.23 | 1.89 | 1.59 |
| West VirginiaCharleston, tilt 38° | 4.55 | 2.84 | 3.69 | 4.34 | 5.01 | 5.20 | 5.71 | 5.52 | 5.73 | 5.15 | 4.58 | 3.93 | 2.91 |
| WisconsinMilwaukee, tilt 43° | 4.55 | 2.92 | 4.23 | 4.82 | 4.81 | 5.31 | 5.47 | 5.86 | 5.61 | 5.19 | 4.00 | 3.38 | 2.99 |
| WyomingCheyenne, tilt 41° | 5.45 | 4.58 | 4.97 | 5.75 | 5.70 | 5.43 | 6.34 | 6.11 | 6.16 | 6.12 | 5.33 | 4.68 | 4.20 |
Where the numbers come from
We asked the PVWatts v8 API for each city's monthly solar radiation (solrad_monthly) with system_capacity=1, module_type=0, losses=14, array_type=0 (fixed open rack), tilt equal to the latitude and azimuth 180 (south). Solar radiation in kWh/m² per day equals peak sun hours. Weather data are NSRDB typical-year files: PSM V3 GOES TMY 2020 for most places and PSM V4 Polar TMY 2023 for Alaska (PVWatts v8 API; NREL is now named NLR). A flat panel, a steeper winter angle, shade or a different city will see different numbers.
Watt-hours from your panels = panel watts × (1 − losses) × peak sun hours. That is what reaches the station's input; the station loses some more charging its battery (see Methods).
- Solar recharge
Panels, a station and your state: days to refill.
- Charge time
Wall, car and solar side by side for 9 stations.
- Station specs
Solar input limits and the rest of the specs.