No relief from the heat as many U.S. cities will see record overnight temperatures

By — John Seewer, Associated Press John Seewer, Associated Press Leave your feedback Share Copy URL https://www.pbs.org/newshour/nation/no-relief-from-the-heat-as-many-u-s-cities-will-see-record-overnight-temperatures Email Facebook Twitter LinkedIn Pinterest Tumblr Share on Facebook Share on Twitter No relief from the heat as many U.S. cities will see record overnight temperatures Nation Jul 13, 2026 5:07 PM EDT Another week of blistering heat will bring even more health risks in the coming days, as overnight temperatures won't provide much relief. The National Weather Service is predicting that more than 90 temperature records across the U.S. will be tied or broken this week through Wednesday — and most of those will be overnight heat records. Grow your mind Subscribe to our Science Newsletter to explore the wide worlds of science, health and technology. Health experts say overnight temperatures that fail to cool down are even more dangerous than daytime temperatures that soar. It has already been a sweltering start to the summer across much of the U.S. due to the long-lasting heat dome expected to blanket much of the country this week. The blistering temperatures over the past few weeks have caused heat-related deaths in New Jersey and helped fuel wildfires in the West. No relief from the heat at night this week Temperatures were not forecast to drop below 80 F (27 C) at night in Fort Lauderdale, Florida; Miami; Tampa, Florida; Galveston, Texas; and Charleston, South Carolina, the National Weather Service said. Over the next few days, places in the Midwest and Northeast known for frigid winters will see nighttime temperatures remain above 70 F (21 C), including Fargo, North Dakota; International Falls, Minnesota; and Portland, Maine. Hot temperatures at night pose a bigger danger Health experts say that high overnight temperatures are particularly dangerous because there's no time for the body's core temperature to cool down and recover from daytime heat. "That's where the health outcomes are amplified, particularly for the elderly and vulnerable communities," said University of Georgia meteorology professor Marshall Shepherd. Just a few degrees of increased body temperature can lead to heatstroke or put too much strain on the heart. Dangers of heat can sneak up on you If temperatures at night don't cool down your body, the health risks more often show up the next day, said Kristie Ebi, a public health and climate scientist at the University of Washington. "Mortality starts the second or third day" because the body's unable to cool, she said on Monday. Being proactive is crucial during a heat wave Early warning signs include heavy sweating, muscle cramps and headache. "It's hard to know you're getting in trouble with the heat. This is why we need to be more proactive," Ebi said. It's important to find a way to cool off, whether stepping into air conditioning or wrapping a cold towel around your neck. And health experts say don't forget to chec