Potentially deadly heat wave envelops most of the nation

More than 55 million people across the nation were under an alert for extreme heat on Sunday and through most of the week ahead as temperatures are forecast to hit triple digits in some parts of the country.

Over the next seven days, 265 million people, or about 82% of the U.S. population, are likely to experience temperatures topping 90 degrees as the official first day of summer arrives on Thursday.

An Excessive Heat Watch was already issued Sunday for parts of New England, including Connecticut, Massachusetts and New Hampshire. The temperature in Concord, New Hampshire, is forecast to reach 101 on Wednesday.

New York City could feel its first heat wave of the year as temperatures are forecast to reach 90 degrees on Wednesday and 94 on Thursday on Friday.

Pittsburgh is also in for a string of hot weather with temperatures expected to soar to 99 degrees on Tuesday, Wednesday, Thursday and Friday.

The heat-wave forecast for Pittsburgh could be the city’s hottest all-time for the month of June. The previous five-day June record occurred in 1994 with a temperature average of 96.4 degrees.

The all-time record for a heat wave in Pittsburgh happened in mid-July 1988 when city residents sweltered for five consecutive days with 98.6-degree temperatures.

Washington, D.C., is also expected to be inundated with 90-degree weather and could flirt with the century mark by Friday.

High temperatures are also forecast for Ohio and southeast Michigan, where an excessive heat watch is also in effect from Monday through Friday.

Daily temperature records are expected to fall this week in Chicago, Green Bay and Cleveland.

Out west, dangerous heat is expected for Texas, Arizona, Nevada and New Mexico.

An excessive heat warning was issued for Phoenix and Tucson, Arizona, where temperatures threatened to hit the 110-degree mark on Sunday.

Roswell, New Mexico, is expected to reach 105 degrees on Sunday and El Paso and Fort Stockton, Texas, are expected to get just as warm.

Authorities warn people enduring such high temperatures to stay hydrated and out of the heat, and to check on elderly neighbors and relatives.

In 2023, there were 2,302 heart-related deaths across the country, a 34% increase from 2022.