Third weather heat dome to hit 70 million across US
About 70 million people in the southern and central United States face excessive heat advisories as a third major weather heat dome of the month builds, locking in 95–105F (35–40C) from the Gulf Coast to the Great Plains and Midwest. Some southwestern desert areas could approach 120F (48C), with the high-pressure “lid” expected to hold the heat into the coming week.
Key Takeaways
- Roughly 70 million Americans are under excessive heat advisories amid July’s third U.S. heat dome.
- Forecast highs of 95–105F span the Gulf Coast, Plains, and Midwest; desert spots may near 120F.
- The National Weather Service warned western Nebraska of extreme heat, with weekend temperatures near 108F (42C).
- Elevated overnight temperatures and humidity leave little relief for vulnerable groups.
- Mid-Missouri’s heat advisory runs through Monday, with slightly cooler, less humid feels-like temps Tuesday.
What is a weather heat dome and why does this one matter?
A heat dome forms when a high-pressure atmospheric system acts like a lid, trapping heat over a region for days or even weeks. According to The Guardian, this is the third major U.S. heat dome event in the past month, spanning a vast swathe from the Gulf of Mexico coast through the Great Plains and the Midwest.
The Washington Post reported the system was forecast to strengthen into the planet’s strongest heat dome at the time, towering over the Rockies and Plains and threatening more records. Earlier this month, a huge heat dome canceled some Independence Day events in the East, and a later western surge pushed Montana to 115F (46C) as temperature records tumbled. The latest setup could potentially break records in the Denver area.
Where will the heat hit hardest this week?
National guidance points to dangerous heat building across parts of the West and Central U.S. through the weekend, then expanding into the Central U.S. and Gulf Coast early next week. Western Nebraska carries an extreme heat warning, with weekend highs forecast near 108F. Broader corridor impacts stretch from the Dakotas toward Texas, with blistering conditions expected to linger across the southern Plains for much of next week.
In Mid-Missouri, KOMU 8 said a heat advisory is active through Monday amid extremely hot, humid air after cooler rains depart. After the advisory expires, temperatures ease only slightly while humidity drops, returning feels-like readings to the 90s on Tuesday.
How dangerous is this heat for people and communities?
Heat is the deadliest weather phenomenon in the United States. Elevated nighttime temperatures and high humidity in this wave are set to provide little respite. Older people, pregnant people, young children, and those with existing health conditions are particularly vulnerable. Local forecasters urge residents to listen to their bodies, drink plenty of water, and stay indoors when possible.
Climate scientists say the pattern matches long-standing projections. “We are experiencing exactly what the climate models in the 1990s said we should experience now,” said Andy Pershing of Climate Central, citing more frequent, severe heatwaves, bigger temperature anomalies, more humidity, and higher overnight temperatures. For more on how climate and forecasting tech shape extreme-weather coverage, see our Future Tech & AI Wonders hub. Across the U.S., firefighters were tackling 88 fires as hot, dry conditions also primed landscapes in Europe and the UK.