Sweltering Heat Wave Holds Central and Southern U.S. in Its Grip for a Second Day

For a second straight day, a relentless heat dome has forced a swath of the central and southern United States into uncomfortable, sometimes dangerous, conditions. The National Weather Service says more than 40 million people are now under extreme‑heat warnings as temperatures climb well above 100°F (38°C) and humidity spikes to oppressive levels.

From the plains of Minnesota all the way down to Mississippi, the heat index—what it actually feels like—has been cruising in the low‑to‑mid‑100s. The dome stretches westward too, with parts of southern California and Nevada seeing scorching highs, and some spots in the Southwest expected to flirt with a blistering 120°F (49°C).

“It’s extraordinarily hot,” said Pete Miller, outreach manager for the homeless‑services network Threshold CoC, while handing out water bottles on a scorching Sunday in Omaha, Nebraska. “People are exhausted, drained by the heat in a way that’s really dangerous. The humidity is insane – you step outside for half a minute and you’re drenched.” Miller added that the oppressive conditions are likely to linger through the night.

It wasn’t just the general public feeling the heat. On Saturday, Rapid City, South Dakota, recorded an all‑time high of 112°F (44°C). In Minnesota, a horse race scheduled at Canterbury Park in Shakopee was scrapped on Sunday because the track simply became too hot for the animals and the spectators.

Bob Oravec, a meteorologist with the NWS, explained that the heat dome is essentially a “lid” of warm air that traps heat close to the ground. “Right now it’s affecting a lot of people right in the middle of the country,” he said. “The core of the heat will shift southward early next week, but the dome also stirs up severe thunderstorms, flash‑flooding and hail around the Great Lakes.” He warned that while a brief lull may arrive mid‑week, another surge of high temperatures could return by the weekend.

Health officials are sounding the alarm, especially for children, seniors and anyone with chronic medical conditions. Heat‑stroke, dehydration and other serious reactions are top concerns. Experts urge anyone in the warning zones to seek air‑conditioned spaces, stay hydrated, and limit exposure to direct sunlight.

Even beyond the immediate crisis, the heat wave is part of a broader trend. According to the National Centers for Environmental Information, the first half of 2026 has already turned out to be the second‑hottest on record for the contiguous United States.