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Extreme Heat Alerts Spread From Southwest to 20 States

Warnings remain active through Thursday evening following forecasts of record-breaking heat.

Aerial view of Boulder Basin, the northwestern arm of Lake Mead, shows the bathtub ring, indicator of long-term water loss, between Boulder City, Nevada, and the Las Vegas metropolitan area on July 3, 2025.
A person wipes sweat from their brow at Badwater Basin in Death Valley National Park, Calif., Sunday, July 7, 2024. Forecasters say a heat wave could break previous records across the U.S., including in Death Valley. (AP Photo/Ty ONeil)
Heat alerts Tuesday
A map created by Newsweek shows the states with a major heat risk on Monday.

Overview

  • Extreme heat warnings cover dozens of counties in Arizona, California and Nevada, including Maricopa, Yuma, San Diego and Riverside, through Thursday at 8 p.m.
  • Heat advisories now span 20 states from the Northwest to the East Coast, urging millions to limit sun exposure and stay hydrated.
  • Temperatures are forecast to reach up to 119°F in the warned regions, with Phoenix expected to peak near 117°F.
  • The National Weather Service warns that overexposure can lead to heat cramps, exhaustion and heat stroke, calling extreme heat the deadliest U.S. weather hazard.
  • OSHA and CDC guidance recommend frequent breaks in shaded or air-conditioned spaces, regular hydration and immediate medical attention for heat-related emergencies.