Three days of misery ends in an hour

The muggy heat wave that choked Boston for three broiling days ended this afternoon when the wind shifted and a backdoor cold front dropped the temperature in the city by 20 degrees in one hour.

By 3 p.m., the mercury in a thermometer at Logan International Airport dipped to 73 degrees when it had sat at 93 degrees just 60 minutes earlier.

“It feels a whole whale of a lot different than it did a few hours ago in Boston,” said Meteorologist Alan Dunham of the National Weather Service in Taunton.

Relief, however, has not yet reached the entire state. Inland cities and towns still had to endure sultry weather at 4 p.m. Just 20 miles northwest of Boston in Bedford, temperatures were still in the 90s.

The winds, which had been blowing hot, sticky air out of the west, shifted to the east and northeast, bringing cooler sea breezes off the Atlantic Ocean. The remainder of the much anticipated cold front is lagging in Maine, New Hampshire and Vermont, and should soon envelope all of Massachusetts, Dunham said.

The weather change is expected to bring some intense thunderstorms late this afternoon which could complicate the evening commute. A severe thunderstorm watch is in effect for Plymouth and Bristol counties and Rhode Island and Connecticut through 10 p.m.

Friday will continue to be cool, Dunham said, with highs in the low 80s, a trend that should hold through the weekend.

“Saturday and Sunday should be gorgeous days,” Dunham said. “A Great weekend.”

Temperatures hit triple digits in some places in New England on Wednesday, with Taunton leading the way at 101 degrees. The heat wave was one of the most intense in the last decade.