A punishing heat wave will bring hot temperatures to eastern US and linger for several days, underscoring how climate change heats things up.
Heat dome brings 115-degree temps to central and southern US
A massive heat dome will push real feels to 115 degrees across the central and southern U.S.
As the clock ticks down the final days of July, thermometers will climb across much of the eastern half of the United States, creating a dangerous and long-lasting heat wave that will put millions at risk of heat stroke and other illnesses.
Those in the path of the heat wave should plan to take extra measures to stay cool through at least July 30. Keep things chill by staying in air-conditioned spaces, visit friends with pools, pile up the popsicles and lemonade and pull out the recipe for your favorite cold summer salad.
“This will be a long duration heat wave, with little to no overnight relief and high humidity levels, leading to an increased danger,” the National Weather Service Weather Prediction Center said on July 24.
Daily highs in the upper-90s to near 100 degrees are forecast to combine with humidity to create conditions where the “feels like” temperatures could exceed 110-115 degrees, according to a July 25 forecast by Jennifer Tate at the prediction center.
A dome of high pressure sitting over the eastern part of the country will help trap the heat while abundant moisture in the air will make actual temperatures feel several degrees warmer. The unusual heat and humidity could linger for several days, keeping heat risk in the major to extreme categories through the end of the month across much of the eastern United States.
The dangerous heat will be longest lasting across the Tennessee Valley/mid-South region and the Southeast into the Carolinas, said a Friday forecast by Jennifer Tate at the Weather Prediction Center. Morning lows in the 70s “will not provide much relief.” Farther north, into the Midwest, Ohio Valley and mid-Atlantic can expect hotter-than-normal temperatures into the 90s.
Forecast maps from the weather service show the United States blanketed in warm shades of purple, red and orange, signifying intense heat. By July 30 or 31, a cold front is expected to help cool things in the Ohio valley region.
Anyone who absolutely must be outside should take extra precautions to stay hydrated and keep their body safe, according to the American Red Cross.
The heat isn’t the only danger presented by the high pressure area dominating conditions. Interactions in the atmosphere around the perimeter of the heat dome are forecast to trigger thunderstorms and heavy rain.
‘Not your grandmother’s heat wave’
It has always been hot during the summer.
“We’ve always had heat waves,” said Max Holmes, president and CEO of the Woodwell Climate Research Center in Woods Hole, Massachusetts. “But it’s happening a lot more, with greater intensity, greater duration and greater frequency.”
“This is exactly what we expected to happen,” Holmes said. “As the earth gets warmer, we see more extremes and it’s the extremes that get us. They kill us. They make us sick.”
Heat may be the most obvious, but there are others, including drought and the extreme rainfall that caused the deadly flash flooding in Texas Hill Country on July 4, he said. These extremes can be seen in the current heat wave, with forecasts for record breaking temperatures under the high pressure area, and intense rainfall in storms around the perimeter of the heat dome.
June 2025 was the seventh hottest June on record, according to data from the National Oceanic and Atmospheric Administration.
During the first two weeks of July 2025, temperatures across the country were an average of 1.5 degrees warmer than the most recent 30-year normal. Historical data from the weather service shows average temperatures in July have trended roughly 2.7 degrees warmer since 1950.
If a human body temperature is normally 98.6 degrees and warmed 2.7 degrees, it would be the equivalent of having a fever of 101.3. In nature, such an increase has a similar effect, scientists explain.
Average overnight temperatures across the country have climbed even higher than daytime high temperatures, the weather service data shows. That means the landscape, trees and buildings don’t get a chance to cool down, so they can heat up even faster the next day.
Extreme levels of heat stress have more than doubled over the past 40 years, according to NASA, and that trend is forecast to continue.
An analysis by Climate Central, published July 21, concluded human-caused climate change made the recent excessive heat at least three times more likely for nearly half the population of the United States.
“This is not your grandmother’s heat wave,” said Kristina Dahl, Climate Central’s vice president of science. “Yes, July is usually a hot month, but climate change is making this heat wave significantly hotter — and therefore more dangerous — than heat waves of the past.”
How hot is too hot for people?
Prolonged exposure to warmer temperatures can cause serious, life-threatening complications including dehydration, a rapid or irregular heart beat and exacerbation of existing medical conditions.
Scientists in recent studies have indicated the warmest temperature that human bodies can withstand without losing their ability to regulate temperature is lower than commonly believed.
They’ve come to rely on a measurement known as wet bulb temperature to determine the dangers. It uses a thermometer with a wet wick over its bulb and measures the effect of humidity on temperatures. Humidity can impair the body’s essential cooling mechanism – sweat doesn’t evaporate.
Scientists previously thought the warmest temperature a human body could take before losing its ability to regulate its own temperature was roughly 95 degrees at 100% humidity or 115 degrees at 50% humidity.
A 2022 study co-authored by scientists at Penn State concluded the actual maximum temperature humans could take for prolonged periods was even lower using a wet-bulb thermometer, about 87 degrees at 100% humidity, even for people who are young and healthy. Among those even more at risk, such as the elderly and young children, the maximum temperature is probably even lower, the study found.
What can you do to protect yourself and others from extreme heat?
In short, the Red Cross advises:
- Know who’s most at risk – Look out for older adults, young children, pregnant women, those with disabilities or medications for a chronic health conditions, people who live alone and athletes.
- Stay hydrated – Drink water every 20 minutes, even if you aren’t thirsty and avoid sugary drinks, caffeine and alcohol.
- Stay cool – Seek out an air-conditioned location if your home gets too hot, limit outdoor activity and dress in lightweight, loose-fitting clothes. If your air-conditioning goes off, it might be cooler outside in the shade than staying inside the house.
- Act fast – Take measures to cool a person down quickly if they develop signs of heat exhaustion or stroke, such as cramps, heavy sweating, clammy skin, dizziness, fainting or nausea and vomiting. Move them to a cooler place, remove extra clothing and cool them with a wet cloth or cool bath and have them sip water or a sports drink, but not “energy” drinks.
Where can you get more information?
Resources are available to learn more about the dangers of heat-related illnesses and how to help yourself and others stay safe, but not as many as there used to be. A heat risk tool maintained by the Centers for Disease Control and Prevention to track heat risk and heat illnesses was taken out of service this year and is no longer active. The website is still available, but no new information is being added.
Trump administration officials have taken steps to curb what they refer to as climate alarmism, and have changed wording about climate change, no longer including it as an environmental topic on the home page of the Environmental Protection Agency, and stopped maintaining other websites, such as Climate.gov and a Centers for Disease Control and Prevention page to track heat risk and heat illnesses. A tool on the CDC page now shows an error message.
Reporting by the administration’s Department of Government Efficiency shows the termination of more than 350 grants that mentioned climate change, including dozens that mentioned heat specifically.
NOAA’s proposed budget for the coming year stated it would no longer support the National Integrated Heat Health Information System, the federal website on heat and heat-related illnesses that brings together information from NOAA and more than a dozen other departments and agencies. For now, the comprehensive guide launched during the Biden administration to try to reduce the rising rate of heat illnesses in the United States is still online.
To Holmes, much of the information being obscured is factual, not political.
“There are combinations of temperature and humidity the human body just can’t tolerate,” Holmes said. “Trying to hide the truth doesn’t help people.”
“I see zero rationale for trying to bury that information. It’s shameful that our government is doing so,” he said. “It’s not a partisan thing, it’s a fact thing.”
Dinah Voyles Pulver, a national correspondent for USA TODAY, covers climate change, weather, the environment and other news. Reach her at dpulver@usatoday.com or @dinahvp on Bluesky or X or dinahvp.77 on Signal.
