Southwestern United States is facing an early heatwave. The temperature in Phoenix is expected to hit 38°C, hard hit in nearly 40 years. The temperature in California, Nevada, and Arizona is increasing 20–30°F. This heatwave is not only posing health risks but also accelerating the melting of the Sierra Nevada snowpack. Because this snow provides a third of California's water, the rapid melt could trigger summer water shortages and an earlier, more intense wildfire season. While low winds are currently keeping fire risks stable in the Southwest, drier conditions near the Rockies remain a concern.