Overview

• More than 90 million Americans are under heat watches, warnings or advisories with daytime temperatures soaring above 100°F and heat index values up to 115°F.
• Sustained high humidity driven by widespread corn evapotranspiration in the Corn Belt has kept overnight lows in the 70s and heightened risks of heat-related illness.
• Heat alerts cover at least 19 states from the Plains to the Southeast, prompting officials to advise residents to stay hydrated, avoid prolonged outdoor activity and seek air-conditioned spaces or cooling centers.
• A Climate Central analysis shows human-caused warming has made extreme July heat at least three times more likely for nearly half of the U.S. population.
• Forecasters say a cold front arriving Thursday night is likely to bring storms and lower temperatures into the mid-80s by Friday, offering the first substantial relief.