Unseasonal Southwest Heatwave Pushes Temperatures into Triple Digits

A dangerous, unusually early heatwave is building across the US Southwest, with Phoenix potentially hitting 100F as temperatures soar 20–30F above normal across California, Nevada and Arizona. The heat—trapped under a heat dome—could push highs above 90F along the coast and approach 110F inland for several days, prompting heat advisories and health warnings. Relief isn’t expected until the weekend or next week. The rapid warmth threatens California’s already dry snowpack by accelerating melt and risking reduced reservoir releases later in the year, while wildfire risk remains low in much of the Southwest due to light winds, though conditions could differ farther east.