The National Weather Service has issued 43 active heat advisories covering parts of 13 states, stretching from the Pacific Coast to the Great Plains, as forecasters warn of dangerous heat index values into the evening hours this week and continued triple-digit highs into next week in parts of the Southwest.
The alerts span California, Colorado, Iowa, Idaho, Kansas, Montana, Nebraska, New Mexico, Nevada, Oklahoma, Texas, Washington and Wyoming, according to the National Weather Service. The heaviest concentration of advisories covers the Texas Panhandle and adjacent Oklahoma counties, where heat index values are forecast to reach up to 105 degrees in Beaver County, Oklahoma, and in Armstrong, Collingsworth, Donley, Gray, Hemphill, Lipscomb and Wheeler counties in Texas, along with the Palo Duro Canyon area, from 1 p.m. to 8 p.m. CDT.
Just south, a separate advisory covers Childress, Cottle, Dickens, Garza, Kent, King, Motley, Stonewall, Briscoe and Hall counties, where the National Weather Service says heat index readings could climb even higher, to between 105 and 109 degrees, from 1 p.m. to 9 p.m. CDT.
In Southern California, the advisory takes a longer view. The Santa Ana Mountains and Foothills are under an advisory running until 8 p.m. PDT Monday, with highs forecast in the 90s to 105 degrees and overnight lows only easing into the mid-70s to lower 80s through the weekend — a pattern the National Weather Service says will limit overnight cooling and compound heat stress. Additional advisories cover San Diego County’s coastal areas and inland valleys, Orange County’s inland and coastal zones, and the San Bernardino and Riverside county mountains.
The National Weather Service is urging residents in affected areas to drink plenty of fluids, stay in air-conditioned spaces, avoid direct sun exposure and check on relatives and neighbors, particularly those without air conditioning. The agency also recommends wearing lightweight, loose-fitting clothing and taking extra precautions for anyone working or exercising outdoors, noting that heat illness can develop quickly under these conditions even for those acclimated to summer heat.
The advisories reflect a broad heat pattern rather than an isolated event, with alerts active simultaneously across the interior West, the northern Rockies and Plains, and the Southwest desert and coastal transition zones. Forecasters caution that the combination of high humidity in the southern Plains and persistent overnight warmth in Southern California creates elevated risk even where daytime highs are not record-setting.