Extreme Heat Warning Issued for Southwest US, Temperatures Up to 118 Degrees Expected

The National Weather Service in Las Vegas has issued an Extreme Heat Warning for portions of northwest Arizona, southeast California, and southern Nevada, effective from Tuesday, August 18, 2026, at 10 AM PDT/MST until Friday, August 21, 2026, at 8 PM PDT/MST. Dangerously hot conditions are expected, with temperatures reaching up to 115 to 118 degrees Fahrenheit in Death Valley and the lower Colorado River Valley, and 107 to 110 degrees elsewhere. Heat-related illnesses will significantly increase during this period.