Millions of Americans across several western states are under Extreme Heat Warnings as a powerful heat dome intensifies, bringing temperatures well above normal and raising the risk of heat-related illnesses. The National Weather Service (NWS) has issued warnings for parts of Arizona and California, where afternoon temperatures are forecast to climb into the triple digits, with some areas approaching 118 degrees through at least Thursday.
Areas Under Extreme Heat Warnings
The hardest-hit locations include the Phoenix metropolitan area, where temperatures are expected to reach 109 to 116 degrees, and southwestern Arizona and southeastern California, with highs ranging from 110 to 118 degrees. The Tucson area is forecast to see temperatures of 107 to 111 degrees, while California's Coachella Valley and San Diego County deserts could reach up to 117 degrees. Overnight temperatures are expected to remain unusually warm, staying in the 80s, limiting cooling opportunities.
Heat Wave in Los Angeles
A heat wave is also affecting Los Angeles County, with temperatures predicted to be 10 to 15 degrees above normal. The NWS issued a heat advisory for non-coastal areas starting at 10 a.m. Tuesday, with temperatures likely to reach 100 degrees or higher. The warmest day is expected to be Wednesday, with highs in the mid-90s to 102 in the valleys and 105 to 107 in the Antelope Valley. The coasts may cool slightly on Thursday due to sea breezes, but inland areas are expected to see little change.
Causes and Safety Measures
The extreme temperatures are being driven by a high-pressure system over the region, according to Spencer Fielding, a meteorologist with the NWS. Officials advise residents to stay hydrated, avoid prolonged sun exposure, and check on vulnerable populations, such as older adults and children. Temperatures are expected to fall over the weekend as moisture returns to the area.