Map shows "heat dome" that could raise temperatures to 100 degrees in Boston
A "heat dome" developing on the East Coast could send temperatures to 100 degrees in Boston next week. As a result, an extreme heat watch is going into effect Sunday morning through Tuesday for much of Massachusetts.
After toiling our way through a difficult spring full of rainy Saturdays, summer has literally and figuratively arrived.
The summer solstice officially occurs at 10:42 p.m. on Friday. Our longest days of the year and highest sun angles are here.
What is a heat dome?
Right on cue, a giant heat dome will be forming over most of the eastern half of the United States. The term "heat dome" is just another way of saying a large area of high pressure. This promotes sinking, warming air over a large area and will lead to numerous record high temperatures being set as well as the first heat wave for many in the Northeast.
It's been about a year since we had a heat wave in the Boston area.
In fact, we had two in 2024 - one in June and one in July, both of which lasted the minimum requirement of three days.
Extreme heat watch in Boston
The fringe days are always the hardest to predict. Some towns could hit 90 on Sunday while others will fall short. Wednesday currently looks to top out in the mid 80s, but we can't rule out that forecast changing.
Monday and Tuesday look like "locks" for temperatures to soar well into the 90s.
In fact, we will likely challenge some record high temperatures on those two days in the city of Boston and throughout New England.
An extreme heat watch is in effect from Sunday morning through Tuesday for the following Massachusetts counties: Suffolk, Plymouth, Bristol, Norfolk, Middlesex, Essex, Worcester, Franklin, Hampshire and Hampden.
Heat could set records in Massachusetts
We are forecasting the record of 95 degrees on Tuesday (set in 2013) to be shattered.
If we were to hit the century mark in Boston, it would only be the 28th time in recorded history and the first occurrence since 2022. It would also equal the all-time June record, set last in 2021.
As of this writing, it's possible that many of our suburbs will nick 100 next Tuesday afternoon.
We will see some "cooler" weather later next week, likely along with a chance for thunderstorms.
If your occupation requires you to be outdoors and in the sunshine for long stretches of time, we urge you to be cautious next week.
When the heat indices reach near or over 100 degrees, heat stroke is a real concern.
Please be sure to check on those without air conditioning or ways to cool down. And of course, don't forget the pets - they get hot too.
