Peak sun hours by state (2026)
Peak sun hours measure how much usable solar energy a location receives each day — the single biggest factor (besides your electricity rate) in how much power your panels produce. Below is the average for every US state, derived from real multi-year solar-irradiance data. Learn more in our peak sun hours guide.
Peak sun hours, all 50 states + D.C.
"Annual kWh per kW" is roughly how much electricity 1 kW of panels produces per year in that state (peak sun hours × 365 × 0.8 for real-world losses).
| # | State | Peak sun hours/day | Annual kWh per kW |
|---|---|---|---|
| 1 | Arizona | 6.6 | 1927 |
| 2 | New Mexico | 6.5 | 1898 |
| 3 | Nevada | 6.4 | 1869 |
| 4 | Hawaii | 5.9 | 1723 |
| 5 | California | 5.6 | 1635 |
| 6 | Florida | 5.5 | 1606 |
| 7 | Utah | 5.4 | 1577 |
| 8 | Texas | 5.3 | 1548 |
| 9 | Colorado | 5.2 | 1518 |
| 10 | Oklahoma | 5.1 | 1489 |
| 11 | Georgia | 5 | 1460 |
| 12 | Kansas | 5 | 1460 |
| 13 | North Carolina | 5 | 1460 |
| 14 | South Carolina | 5 | 1460 |
| 15 | Arkansas | 4.9 | 1431 |
| 16 | Idaho | 4.9 | 1431 |
| 17 | Louisiana | 4.9 | 1431 |
| 18 | Mississippi | 4.9 | 1431 |
| 19 | Wyoming | 4.9 | 1431 |
| 20 | Missouri | 4.8 | 1402 |
| 21 | Nebraska | 4.8 | 1402 |
| 22 | Tennessee | 4.7 | 1372 |
| 23 | Alabama | 4.6 | 1343 |
| 24 | South Dakota | 4.6 | 1343 |
| 25 | Virginia | 4.6 | 1343 |
| 26 | Iowa | 4.5 | 1314 |
| 27 | Kentucky | 4.5 | 1314 |
| 28 | Maryland | 4.5 | 1314 |
| 29 | Minnesota | 4.5 | 1314 |
| 30 | North Dakota | 4.5 | 1314 |
| 31 | Delaware | 4.4 | 1285 |
| 32 | Washington, D.C. | 4.4 | 1285 |
| 33 | Illinois | 4.4 | 1285 |
| 34 | Indiana | 4.4 | 1285 |
| 35 | Montana | 4.4 | 1285 |
| 36 | New Jersey | 4.4 | 1285 |
| 37 | Massachusetts | 4.3 | 1256 |
| 38 | Rhode Island | 4.3 | 1256 |
| 39 | West Virginia | 4.3 | 1256 |
| 40 | Wisconsin | 4.3 | 1256 |
| 41 | Connecticut | 4.2 | 1226 |
| 42 | Maine | 4.2 | 1226 |
| 43 | Michigan | 4.2 | 1226 |
| 44 | New Hampshire | 4.2 | 1226 |
| 45 | New York | 4.2 | 1226 |
| 46 | Ohio | 4.2 | 1226 |
| 47 | Pennsylvania | 4.2 | 1226 |
| 48 | Vermont | 4.1 | 1197 |
| 49 | Oregon | 4 | 1168 |
| 50 | Washington | 3.8 | 1110 |
| 51 | Alaska | 3 | 876 |
Want the cost and payback too? See solar panel cost by state.
Frequently asked questions
What are peak sun hours?
A peak sun hour equals one hour of sunlight at 1,000 W/m² — full-strength sun. Your daily peak sun hours represent the usable solar energy your location receives, which is what determines how much power each panel produces.
How many peak sun hours do I need for solar?
Solar works across a wide range. More peak sun hours mean fewer panels for the same output, but even locations with 3.5–4 hours support solar — they just need slightly larger systems.
Which state gets the most peak sun hours?
The desert Southwest leads — Arizona, New Mexico, and Nevada top the table with roughly 6–7 peak sun hours a day, while the Pacific Northwest sits closer to 3.5–4.