An unusually early heat wave has gripped the Desert Southwest, with Phoenix recording its first 110-degree day on April 12 — the earliest such reading in the city's history. Las Vegas, Tucson, and Palm Springs also set daily temperature records over the weekend as a strong ridge of high pressure built across the region.
The excessive heat prompted the National Weather Service to issue heat advisories for much of southern Arizona and Nevada through Wednesday. Officials in Maricopa County activated cooling centers and urged residents to limit outdoor activity during peak afternoon hours.
Climatologists say the event fits a broader trend of heat waves arriving earlier and lasting longer across the American Southwest. The previous record for Phoenix's earliest 110-degree day was April 18, 2020. The current ridge is expected to weaken later this week, bringing temperatures back to near-seasonal averages by Friday.
