David Epstein: Labor Day weekend starts cooler, then ends hot and humid

Here's your weekend weather forecast.

extreme heat in boston
Children play in a fountain on the Rose Kennedy Greenway as temperatures rose into the high 90s this week. –John Cetrino / EPA-EFE / Shutterstock

As we head into Labor Day weekend, temperatures will take a break from their recent extremes. Don’t get too used to the cooler weather, though: More heat and humidity will arrive later this weekend and, especially, all of next week.

High pressure off the Atlantic has been on steroids this summer, and although it will relax its grip on New England on Friday and Saturday, it will once again become a dominant force in our weather through the first week of September. If you want a long-term break from the heat and humidity, you’ll have to wait until the middle of September at the earliest.


Until then, here’s your weather forecast for the holiday weekend:

Friday will be in the mid 70s.

High temperatures Friday
High temperatures Friday will be in the mid 70s. —David Epstein / NOAA data

Temperatures Friday will be in the loaded mid 70s with the wind coming in off the water. 

We won’t be cloud-free this weekend; look out for the heaviest cloud cover Friday and the first part of Saturday.

Saturday will be pleasant.

High temperatures Saturday
Temperatures Saturday will be below average. —David Epstein / NOAA data

We will also see temperatures under 80 degrees on Saturday.

If you like this type of summertime weather, enjoy it while it lasts. By Sunday, readings will once again get into the 80s, and you’ll notice an increase in humidity.

Sunday will be warmer.

High temperatures Sunday
Temperatures Sunday will be above average. —David Epstein / NOAA data

Temperatures Sunday will be above average for this time of year. Expect temps in the mid 80s in Greater Boston and cooler along the Cape and islands.

I’m not forecasting any precipitation this weekend, but there is a small chance of a quick sprinkle Sunday night or Monday as humid air arrives. Otherwise, the weekend will be filled with a blend of clouds and sunshine, and lower dew points to start, but high dew points to finish.

The below loop of the dew points shows dry air moving in for a short period before the higher humidity comes back from the south. Notice that dew points at or above 70 surge back into New England, which means by the time Sunday afternoon arrives — and especially on Labor Day — it’s going to once again feel tropical.



Dew points will significantly increase later this weekend. (COD Weather)

Monday will be hot and humid.

Labor Day high temperatures
High temperatures on Monday will be in the mid to upper 80s, and cooler on the Cape and islands. —David Epstein / NOAA data

Some areas will reach 90 degrees Monday for the start of another possible heat wave. Water temperatures are warm because of all the recent heat, so if you’re heading to the beach, you’ll be able to get in a swim.

Over Cape Cod and the islands, you can expect much of the same forecast. There may be a few more clouds late in the weekend as the humidity arrives.