Map: Here’s how humid and warm it will be in Massachusetts on Tuesday

Forecasters say the “excessive heat” will return later this week.

Boston, MA - 04/011/17 - Running or in repose, it was a day to enjoy record-breaking heat near the New England Aquarium on the waterfront.   (Lane Turner/Globe Staff) Reporter:  (in caps)  Topic: ()
–Lane Turner / The Boston Globe, File

Primary day in Massachusetts is going to be hot and sticky.

The National Weather Service is predicting Tuesday “will be warm and very humid,” but forecasters said the temperatures Massachusetts residents will experience as they head to the polls will be “somewhat cooler” than what the region experienced on Labor Day.

Most areas will top out in the 80s, while the CT River Valley will reach the low 90s,” the service said. “A Heat Advisory is in effect through 6 p.m. in Connecticut, much of Rhode Island, and part of the CT River Valley in Massachusetts.”

According to the service, slight relief from the heat is only temporary. “Excessive heat and humidity” are expected to return Thursday with some possible showers and thunderstorms.