Temperature climbs to 88 in Boston — not quite enough to be the start of a heat wave



It was hot out there, but not quite as bad as it could have been. As of 5 p.m., Logan International Airport reached 88 degrees — the high for the day — falling two degrees short of the 90-degree mark needed to begin an official heat wave.


A heat wave is defined as three consecutive days with temperatures at 90 or higher. But don’t lose hope, National Weather Service meteorologist Alan Dunham said, it’s possible Logan could reach 90 or more Friday, Saturday, and Sunday.


The humidity that’s been on the rise all day will only be worse Friday. Winds from a Bermuda High will blow from the southwest, bringing tropical air and causing hot, hazy, and humid conditions.


Though the radar has been quiet this afternoon, parts of the South Shore could see an isolated shower or thunderstorm into the evening. The rest of the region should remain dry, forecasters said.


Overnight, look for lows to dip into the high 50s and low 60s, though urban centers could stay as high as 70 degrees, forecasters said in a discussion posted online.


Dunham recommends people beat the heat by staying hydrated, wearing light clothing, and exercising outside only in the early morning or evenings. He also suggested that people keep an eye on elderly neighbors.


Friday’s heat will feel even more oppressive, Dunham said, thanks to even higher dewpoints and the southwesterly wind. Expect highs to reach the mid-90s.


Saturday should be a carbon copy of Friday, Dunham said, and it might be the perfect time to go to the beach — with a hearty layer of sunscreen, of course. Sunday’s weather shouldn’t differ from Friday and Saturday much, either, at least through the afternoon.


The blast of heat is quite a contrast with recent cool temperatures that brought a touch of snow to Worcester County last week.


Sunday night things are expected to begin to change. Thunderstorms are forecast to roll in ahead of a cold front.


Temperatures will finally ease back down Monday, with highs in the 70s providing a welcome relief from the sizzling weekend, Dunham said. Showers and thunderstorms are also possible throughout the day.


Lauren Dezenski can be reached at lauren.dezenski@globe.com. Follow her on Twitter @LaurenDezenski.