Early-season heatwave intensifies across western United States, Extreme Heat Warnings issued

An anomalously early-season heatwave intensified across the western United States on March 18, 2026, with Extreme Heat Warnings in effect for parts of the Desert Southwest and temperatures forecast to expand east into the Rockies and Great Plains by March 20. Highs are expected to reach 40–44°C (104–112°F) in the hottest desert regions, with numerous daily and some monthly March records likely to be broken. Source