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Summer-like heat is here, but water still too cold to swim, experts say

Summertime sunshine is headed to Massachusetts this weekend, with temperatures expected well into the ‘80s for much of the state, particularly inland locations, according to forecasters.

“It will feel like early #summer for many tomorrow with high temperatures more typical of late June/early July! ”the National Weather Service in Norton tweeted Friday night. “If you want to cool off, head to the coast.”

But don’t let the sudden surge of warmth fool you into thinking it’s okay to swim in the ocean, lake, pond or other favorite watering hole.

Water temperatures will remain in the mid-40′s for most of the state, with only the southside of Cape Cod reaching nearing 50 degrees, according to the weather service.


With “water temperatures in that range, you’ve got to be very leery of hypothermia,” said meteorologist Alan Dunham.

According to the National Center for Cold Water Safety, “any water temperature below 70″ should be treated with caution. Swimming in water between 50 and 60 degrees can bring on sudden cold shock, the center says.

The US Coast Guard is also warning boaters to stay safe on the water. A video posted to Facebook demonstrates how motor skills slow down in severe cold water.

It takes a seaman less than 15 seconds to untie a knot with his dry hands. But after submerging his hands in 48 degree seawater for 60 seconds, it takes more than 15 seconds to untie the same knot, according to the video.

“So as you can see here, even though the air temp is warming up a lot,” a seaman says. “What you really need to watch out for is the water temp.”

Dunham noted that when it’s 80 degrees outside and people try to swim in 50 degree water it can be “a shock to your system.”


Just because it feels warm outside doesn’t mean the water is warm,   Dunham  said.

“The water takes a long time to warm up,” Dunham said.