A severe heat wave gripped central and southern parts of the United States for a second consecutive day, with at least 40 million people under extreme heat warnings. Heat indexes exceeded 100°F (38°C) across a vast region stretching from Minnesota to Mississippi and extending west into southern California and Nevada. Some areas in the Southwest were expected to reach 120°F (49°C), according to the National Weather Service (NWS). The extreme conditions were attributed to a heat dome, a meteorological phenomenon where atmospheric conditions trap and intensify heat.
Pete Miller, an outreach manager for the homeless services network Threshold CoC, described the conditions in Omaha, Nebraska, as "extraordinarily hot," noting that many residents were exhausted and at risk. "The humidity is insane," he said. "You stand outside for 30 seconds and you get drenched. And it’s going to be like that all night."
On Saturday, Rapid City, South Dakota, recorded an all-time high of 112°F (44°C). A horse race at Canterbury Park in Shakopee, Minnesota, was canceled due to the heat. Bob Oravec, an NWS meteorologist, stated that the heat was affecting a broad swath of the central U.S. and would shift southward by early next week.
The heat dome also contributed to severe thunderstorms, flash flooding, and hail around the Great Lakes on Sunday, with the potential for heavy storms expected to move east in the coming days. "If you have a heat dome in one part of the country, you’ll have a different corresponding weather in another part," Oravec explained. "It’s all related."
Temporary relief was expected to reach the central U.S. by midweek, though high temperatures were forecast to persist in other regions.