A persistent heat dome is intensifying across the southern and southwestern United States, exposing 98 million people to major or extreme heat risks through the end of August, according to the National Oceanic and Atmospheric Administration (NOAA).
On Monday, Dallas tied its hottest overall day on record at 97.5°F, with a daytime high of 109°F and an overnight low of 86°F. Forecasters project Dallas may reach or exceed 100°F on 27 of the remaining 31 days in August, one short of the 2011 record. In Oklahoma City, temperatures hit 108°F, matching the daily record, while a location near Chickasha, Oklahoma, recorded 115°F—the regional peak for the day.
The heat dome, which has driven these extremes, is expected to persist until at least early September, with the core shifting westward toward New Mexico, Arizona, and Southern California. Phoenix is forecast to see highs between 106°F and 118°F this week, while Texas braces for near-record temperatures potentially reaching 112°F in multiple areas. Oklahoma has already logged 18 days at or above 100°F this month, nearing the 2011 record of 20 days.
Heat warnings span seven states as risks escalate
The National Weather Service (NWS) has issued extreme heat warnings or advisories for Arizona, Arkansas, California, Louisiana, New Mexico, Oklahoma, and Texas, covering more than 50 million people. In California and Arizona, warnings remain in effect through Wednesday and Saturday, respectively, heightening concerns over heat exhaustion and heat stroke.
The NWS describes the conditions in Texas as “major” or “extreme” on its HeatRisk scale, the two highest levels on a five-stage alert system. “Extreme” conditions are defined as those providing “no overnight relief”, increasing vulnerability for populations without access to cooling or hydration.
Health and wildfire risks mount as heat persists
Meteorologists warn the prolonged heat dome poses significant health risks, particularly for vulnerable groups, including outdoor workers, elderly populations, and those without reliable air conditioning. The NOAA HeatRisk tool highlights that millions in the Southwest and southern Plains face major or extreme impacts, with heat-related illnesses a growing concern.
In addition to human health threats, the extreme temperatures raise wildfire risks, especially in dry regions of New Mexico, Arizona, and Southern California, where low humidity and high winds could exacerbate fire conditions. Climate scientists note that such prolonged heat events are becoming more frequent and intense, aligning with broader trends in climate change.
Regional breakdown: Where the heat is worst
- Texas: Dallas, Fort Worth, Houston, San Antonio, Austin, Lubbock, Odessa, and El Paso are all under heat warnings. Dallas may set a new record for 100°F days in August.
- Oklahoma: Oklahoma City tied a daily record at 108°F, while areas near Chickasha reached 115°F.
- Arizona: Phoenix and Tucson face highs between 106°F and 118°F, with warnings lasting through Saturday.
- California: San Diego and Los Angeles are under heat advisories, with warnings in effect through Wednesday.
- New Mexico: Albuquerque and surrounding areas are expected to experience record-breaking heat, with little overnight relief.
Long-term outlook: No immediate end in sight
The heat dome shows no signs of weakening until early September, according to meteorological models. While the core of the heat shifts westward, the southern Plains and Texas will continue to endure dangerous conditions for the foreseeable future. Officials urge residents to check on neighbors, stay hydrated, and limit outdoor activities during peak heat hours.