A "heat dome" has developed on the East Coast that could send temperatures to 100 degrees in Boston this week. As a result, an extreme heat warning is in effect now through Tuesday for much of Massachusetts.

The thermometer at Boston Logan International Airport showed 102 degrees as of 5:23 p.m. Tuesday, according to the National Weather Service’s Boston office. The 102-degree reading set the record for the hottest ever June temp in city history. It broke the previous 100-degree June days in 2021, 1952, and 1925.