A warm front approaches Tuesday night and early Wednesday. Temperatures will hold in the 60s to near 70 Tuesday night, and the humidity will still be in the tolerable range when you get up Wednesday.
Heat intensifies Wednesday
Sometime in the late morning and early afternoon, Wednesday, dew points are going to surge into the lower 70s, and that’s when the air will become completely tropical, along with temperatures in the low to mid-90s.
The heat index, or “feels like” temperature, on Wednesday will hit a scorching 109 degrees in parts of New England.Boston Globe
Temperatures will peak Wednesday through Friday a little above or below the 100-degree mark, depending on where you are, but it’s about as hot as it gets around here.
The forecast across Boston over the next seven days.Boston GlobeDew points are expected to rise into the 70s, making it feel stifling hot and uncomfortable.Boston Globe
An Extreme Heat Warning and Watch have been issued for Wednesday morning into Saturday, the Fourth of July, for Massachusetts and the rest of New England, except for Cape Cod and the northern tier, as heat index values reach dangerous conditions — 100 to 112 degrees. If you need to do any outdoor activities, you can certainly be outside on Tuesday and the first few hours after sunrise on Wednesday will be fine, but once we get to the afternoon and even into the early evening, it’s going to be pretty intolerable for any strenuous work.
An Extreme Heat Warning has been issued for parts of Southern New England.Boston GlobeHeat impacts will reach “extreme” levels across the Greater Boston area on Thursday.Boston Globe
Heat dome driving all of this sweltering weather
This heat wave is part of a larger high-pressure system, or “heat dome,” that stretches from the middle of the country all the way to the East Coast. When you get high pressure, the air is sinking and that sinking air tends to warm up. When high pressure is stuck in the same position, the warming becomes more pronounced each day, and that’s what’s going to happen this week.
The moderate levels of humidity to start the work week will turn into oppressive levels by midweek, making the extremely hot weather feel even worse. As a matter of fact, the European forecast model has dew points well into the mid- to upper 70s for Thursday, which would create heat indices of 105 to 110 degrees. This is why, if you do have outdoor activities, you’re going to want to get them done very early in the morning. With the sun rising before 5:15 a.m., you’ll have a few hours before 8 or 9 a.m. without dangerous heat.
The best place to hang out this week will be the beach, but remember the sun is incredibly strong now, so be careful and wear sunscreen.
Extreme heat to break records
The last time we reached the triple digits in the Boston area was June 24, 2025, when it hit 102 degrees. The all-time high in Boston was set on the Fourth of July, 1911. The record for Thursday, which is expected to hit 102, is 98 degrees, so obviously we might just set a new record. Those are daily records and we continue to set new daily records on a regular basis, especially on the higher end of the scale.
Tuesday-Wednesday breakdown
Greater Boston: Look for plenty of sunshine on Tuesday with highs 78 to 85. It will turn hot after a morning shower on Wednesday with highs near or above 90.
Central/Western Mass.: Temperatures will be in the 80s to near 90 on Tuesday with moderate humidity. After a morning shower Wednesday, it becomes very humid with temperatures in the 90s.
Southeastern Mass.: Look for high temperatures in the upper 70s to low 80s right at the beaches and well into the 80s inland on Tuesday with mostly sunny skies. It becomes very humid and hot on Wednesday with highs in the 90s, cooler at the beach.
Cape Cod and the Islands: Look for comfortable levels of humidity on Tuesday with lots of sunshine. There might be an early shower on Wednesday. Temperatures will be in the 70s to lower 80s on Tuesday and in the upper 70s to mid-80s on Wednesday
Rhode Island: South County will be the most comfortable over the next couple of days with temperatures in the upper 70s to near 80, but it’s in the 80s to near 90 elsewhere on Tuesday and in the lower to mid-90s Wednesday.
New Hampshire: Look for sunny skies both Tuesday and Wednesday. Temperatures will be 85 to 90 on Tuesday and 90 to 95 on Wednesday.
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