A May 2026 USA TODAY analysis of heat index data from 310 major cities found that roughly 8 in 10 cities have seen more days per year with a heat index of 90°F or higher since 1985.
The USA TODAY report adds:
Cities across the South, Southwest and Southeast saw the sharpest increases, while only the Northern Rockies and Plains and the Upper Midwest experienced a decline.
What is making matters worse is that most cities have longer streaks of 90 plus heat days, and they are hitting the first 90-degree day earlier in the year and seeing the last one later, the USA TODAY analysis found.
What we know: Days this hot dramatically increases water consumption and water waste.
