More than 70 million people in the United States were under extreme heat alerts Monday as a heat wave moved eastward, and the mid-Atlantic and New England were likely to see highs in the 90s as the week progresses. Excessive humidity will make it feel even more oppressive.
The U.S. last year saw the most heat waves, consisting of abnormally hot weather lasting more than two days, since 1936. Officials again warned residents to take precautions.
Much of the Midwest and Northeast were under heat warnings or watches.
The heat has been especially dangerous in recent years in Phoenix, where 645 people died from heat-related causes in 2023, which was a record. Temperatures there hit 112 degrees Fahrenheit (44.4 Celsius) on Saturday. Weather service forecasters say the first two weeks of June in Phoenix have been an average of 5.6 degrees Fahrenheit hotter than normal — the hottest start to June on record there.
A meteorologist with the National Weather Service in Phoenix, Ted Whittock, advised reducing time outdoors between 10 a.m. and 6 p.m., staying hydrated and wearing light, looser fitting clothing. More than 100 cooling centers were open in the city and surrounding county, including two new overnight ones.
