AUGUST 25, 2026
Heat wave puts more than 80 million under warnings as climate scientists link rising temperatures to human-caused warming
More than 80 million people are under an Extreme Heat Warning or Heat Advisory through the week, according to the National Weather Service, which described the heat dome as "steamy air-mass even by mid-to-late August standards." Dangerous triple-digit temperatures are expected to persist across the South-Central U.S. and expand into the Southwest, where highs could reach 110 degrees or more. Overnight temperatures are also remaining elevated, increasing the risk of heat-related illness.
The National Weather Service placed more than 80 million Americans under an Extreme Heat Warning or Heat Advisory this week, with the Southern Plains and Lower Mississippi Valley expected to see temperatures well above 100 degrees Fahrenheit through midweek. The desert Southwest, including parts of Arizona and New Mexico, could also break heat records, with daytime highs potentially reaching 110 degrees or higher by the end of the week.
Scientists have established a well-documented connection between human-caused climate change and the frequency and intensity of heat waves. Michael Wehner, a senior scientist at Lawrence Berkeley National Laboratory who studies extreme weather, told NPR that for typical heat waves — such as the hottest day of the year or the hottest day every ten years — climate change has increased temperatures in the U.S. by 3 to 5 degrees Fahrenheit. The average number of heat waves the U.S. experiences has doubled since the 1980s, according to NPR's reporting.
The health dimension of the current event centers not only on daytime highs but on overnight temperatures that offer little relief. The heat index — which combines air temperature and relative humidity — is forecast to reach between 105 and 115 degrees for parts of southern Arizona, Texas, Louisiana, and northern Florida. Humid heat is particularly dangerous, NPR reported, because sweat does not evaporate effectively in high humidity, preventing the body from cooling down.