Published: 16:19 BST, 24 August 2026 | Updated: 18:09 BST, 24 August 2026
A massive heat dome engulfing the southern US is set to roast seven US states for days as temperatures in some areas soar past 110 degrees.
More than 50 million people living in Arizona, Arkansas, California, Louisiana, New Mexico, Oklahoma and Texas have been placed under extreme heat warnings or heat advisories by the National Weather Service (NWS) on Monday.
Texas is forecasted to be the hardest hit, with Dallas, Fort Worth, Houston, San Antonio, Austin, Lubbock, Odessa and El Paso all impacted by the high-pressure system blanketing the Southwest.
Phoenix and Tucson in Arizona, San Diego and Los Angeles in California, Shreveport in Louisiana and Oklahoma City, Oklahoma, have all been warned of the potentially deadly combination of extreme heat and high humidity lasting until at least 8pm local time tonight.
In California, the heat warnings will remain in effect until Wednesday, and in Arizona, the life-threatening weather is expected to last until Saturday night – extending the risk of residents experiencing heat exhaustion or heat stroke.
A spokesman for the NWS said: 'An extreme heat warning means that a period of very hot temperatures, even by local standards, will occur.'
Temperatures in the Phoenix area are expected to reach between 106 and 118 degrees Fahrenheit in the afternoons this week.
In Texas, forecasters are bracing for near-record temperatures that could reach 112F in multiple areas on Monday, affecting roughly 25 million people in that state alone.
A billboard in Phoenix, Arizona, records an outdoor temperature of 118 degrees in 2023
Extreme heat is expected to affect millions on August 24, with multiple states issuing warning throughout the week. The areas in purple reveal the most extreme emergency
NWS described the conditions in Texas on Monday as 'major' or 'extreme' on their heat risk guidance chart – the two most serious levels on the five-stage alert system.
Extreme describes weather where there will be 'no overnight relief' from the heat, and conditions that will affect anyone who does not have air conditioning or fails to hydrate properly while outdoors.
Dallas, Fort Worth, Austin and Houston have all been listed in the extreme heat zone on Monday.
By Wednesday, the worst of the heat and humidity has been projected to shift west, towards Arizona and Southern California, impacting Phoenix, Tucson and Los Angeles.