Summer officially begins Saturday with a weekend of warmth and sunlight sweeping Massachusetts.
The new season starts at 5:43 p.m. when the summer solstice begins, according to the National Weather Service in Norton. The summer solstice is the longest day of the year when the sun takes its widest path through the sky.
The weather service is reminding Massachusetts residents to stay cool as weekend temperatures reach the low 90s inland and low 80s on the Cape and Islands.
“It’s going to feel like summer-like warmth today and tomorrow,” said Bill Leatham, a meteorologist at the National Weather Service in Norton. “Folks heading outside should try to avoid strenuous activities, wear lighter clothing, and make sure to have plenty of water and fluids.”
Boston is expected to hit 90 degrees Saturday with no precipitation, according to the weather service. Central and Western Massachusetts will hit the upper 80s and may get a brief shower or thunderstorm Saturday afternoon.
The weather will remain sunny and warm Sunday as temperatures hit the low 90s.
“The warm temperatures and muggy feel continue into Tuesday. It doesn’t look like until later this week that we’ll see a break from the heat. The best shot of any precipitation is on Wednesday in Western and Central Massachusetts,” Leatham said.
Temperatures in Boston are expected to reach the low 90s throughout the week before cooling off to the low 80s Thursday, according to the weather service. A cold front is set to move through Massachusetts Thursday.
The weather service is warning beachgoers to drink water as beaches reopen Saturday.
“Folks should make sure they have sunscreen to avoid getting sunburnt, drink plenty of fluids, and take it easy. If it’s starting to get hot, go indoors into some sort of air conditioning,” Leatham said.
Alyssa Lukpat can be reached at alyssa.lukpat@globe.com. Follow her on Twitter @AlyssaLukpat.