Heat Dome Intensifies: 40 Million Under Extreme Heat Warnings Across U.S.
A significant heatwave continues to grip central and southern parts of the United States, with at least 40 million people under extreme heat warnings as of Sunday, July 26, 2026 (Source time: not specified). The National Weather Service (NWS) reports that heat indexes have soared above 100°F (38°C) from Minnesota to Mississippi, extending westward into southern California and Nevada. In parts of the Southwest, temperatures are expected to reach as high as 120°F (49°C). Meteorologists attribute the sweltering conditions to a heat dome, a weather phenomenon that traps heat and prolongs high temperatures. The heatwave has already caused disruptions, including the cancellation of a horse race in Shakopee, Minnesota, and has led to record-breaking temperatures, such as 112°F (44°C) in Rapid City, South Dakota. 
