Annual Heat-Stress Days by State
NOAA publishes 30-year climate normals (mean temperature) and humidity. We project days-above-90°F per year using a piecewise model with humidity adjustment. Hot + humid is harder on people, structures, and HVAC equipment than hot + dry — wet-bulb temperature, not air temperature, is what the body responds to.
Hottest state Florida 70 estimated heat-stress days · 72.1°F annual mean
Coolest state Wyoming 0 estimated heat-stress days · 43.3°F annual mean
States above 100 days 0 where heat-related cooling load dominates the energy bill
States ranked by estimated heat-stress days
| # | State | Annual Mean °F | Humidity % | Heat-Stress Days | Annual Electricity |
|---|---|---|---|---|---|
| 1 | Florida | 72.1°F | 75% | 70 | $1,970 |
| 2 | Hawaii | 71.7°F | 73% | 67 | $2,465 |
| 3 | Louisiana | 66.7°F | 78% | 47 | $1,754 |
| 4 | Texas | 65.6°F | 64% | 39 | $2,183 |
| 5 | Mississippi | 63.5°F | 76% | 35 | $1,955 |
| 6 | Georgia | 63.2°F | 72% | 33 | $1,888 |
| 7 | Alabama | 62.8°F | 72% | 31 | $2,235 |
| 8 | South Carolina | 62.5°F | 72% | 30 | $1,982 |
| 9 | Arkansas | 60.5°F | 70% | 23 | $1,696 |
| 10 | North Carolina | 58.6°F | 72% | 20 | $1,782 |
| 11 | Arizona | 62.1°F | 36% | 18 | $1,908 |
| 12 | Oklahoma | 59.8°F | 62% | 18 | $1,704 |
| 13 | Tennessee | 57.8°F | 70% | 18 | $1,844 |
| 14 | California | 59.5°F | 55% | 16 | $2,093 |
| 15 | Delaware | 55.6°F | 72% | 15 | $1,889 |
| 16 | Kentucky | 56.0°F | 70% | 15 | $1,749 |
| 17 | Virginia | 55.7°F | 68% | 14 | $2,052 |
| 18 | Maryland | 55.1°F | 68% | 13 | $2,349 |
| 19 | Missouri | 55.0°F | 68% | 13 | $1,724 |
| 20 | Indiana | 52.1°F | 72% | 10 | $1,807 |
| 21 | Kansas | 54.5°F | 62% | 10 | $1,625 |
| 22 | Illinois | 52.1°F | 70% | 9 | $1,465 |
| 23 | New Jersey | 52.6°F | 68% | 9 | $1,855 |
| 24 | Ohio | 51.3°F | 72% | 9 | $1,740 |
| 25 | West Virginia | 51.8°F | 72% | 9 | $1,988 |
| 26 | Alaska | 32.7°F | 75% | 8 | $1,744 |
| 27 | Maine | 42.6°F | 72% | 7 | $1,770 |
| 28 | Michigan | 45.5°F | 72% | 7 | $1,460 |
| 29 | Rhode Island | 50.5°F | 70% | 7 | $1,990 |
| 30 | Vermont | 43.2°F | 72% | 7 | $1,488 |
| 31 | Washington | 49.8°F | 72% | 7 | $1,554 |
| 32 | Wisconsin | 44.3°F | 72% | 7 | $1,449 |
| 33 | New Hampshire | 44.4°F | 70% | 6 | $1,751 |
| 34 | Pennsylvania | 49.7°F | 70% | 6 | $1,932 |
| 35 | Connecticut | 49.6°F | 68% | 5 | $2,563 |
| 36 | Iowa | 48.2°F | 68% | 5 | $1,442 |
| 37 | Massachusetts | 48.4°F | 68% | 5 | $2,136 |
| 38 | Minnesota | 42.3°F | 68% | 5 | $1,513 |
| 39 | New York | 47.1°F | 68% | 5 | $1,837 |
| 40 | Oregon | 50.0°F | 68% | 5 | $1,649 |
| 41 | Nebraska | 49.2°F | 62% | 4 | $1,411 |
| 42 | North Dakota | 41.4°F | 64% | 4 | $1,575 |
| 43 | New Mexico | 54.1°F | 38% | 3 | $1,135 |
| 44 | South Dakota | 45.7°F | 60% | 3 | $1,623 |
| 45 | Colorado | 46.0°F | 42% | 0 | $1,343 |
| 46 | Idaho | 45.7°F | 48% | 0 | $1,400 |
| 47 | Montana | 43.7°F | 50% | 0 | $1,307 |
| 48 | Nevada | 51.7°F | 30% | 0 | $1,488 |
| 49 | Utah | 49.2°F | 40% | 0 | $1,237 |
| 50 | Wyoming | 43.3°F | 44% | 0 | $1,329 |
Method
- Heat-stress days = piecewise function of NOAA annual mean temperature, with humidity adjustment up to ±15 days.
- Not actual NOAA data. True heat-stress days require NOAA Climate Data Online daily-grain. The model approximates that distribution from the annual mean — directional, not parcel-precise.
- Why electricity is shown alongside. Cooling load drives the largest share of summer electricity cost in southern states; pair the heat-stress count with the per-state annual electricity bill for a full thermal-cost picture.
Sources: NOAA Climate Normals, EIA Electric Power Monthly.