See Day-by-Day Forecast as Heat Wave Engulfs U.S. Ahead of the July 4 Weekend

Go here for the latest on the heat wave. Millions of people are facing dangerous and potentially record-breaking heat, as a heat wave grips much of the central and eastern United States through the Fourth of July weekend. Forecasters said temperatures were expected to soar into the 90s and low 100s across large parts of the country, with many places expected to challenge or break daily records, as the heat intensifies and spreads east. From Chicago to New York, city and county officials began opening cooling centers and directing people to take the forecast seriously. Mayor Zohran Mamdani of New York City, where the highest temperatures were expected in the second half of the week, set in motion what he called an “unprecedented, historic heat emergency plan.” Michael Muccilli, a meteorologist with the National Weather Service, called the forecast “the hottest temperatures so far this season” on Monday afternoon. He warned that the danger would be “further heightened” because of the number of people expected to spend time outdoors in the lead-up to the long holiday weekend.