Pack away the sweaters — a sizzling three-day stretch of of weather is about the roast NYC along with much of the eastern part of the country.

The region will trade cool spring breezes for a full-blown early summer scorcher, according to the National Weather Service.

“Heat will be making headlines for much of the Eastern US for the first half of the week,” said the NWS.

“It’s going to be shock because it will happen so suddenly. The temperatures have been cool lately and it’s usually in the low ’70s in mid-May,” Carl Erickson, a senior meteorologist at AccuWeather, told the Post.

“The hottest days will be on May 19 and 20. The temperature on Tuesday is predicted to be 95 degrees, and 92 degrees on Wednesday, then by Thursday temperatures will begin dropping,” he said.

The record temperature in New York City for May 19 was set in 1962, when the mercury hit 99 degrees. The record for May 20 was set in 1996, when the temperature hit 96 degrees, added Erickson.

Humidity will team up with the heat to make conditions oppressive in spots.

A sprawling dome of high pressure settling on the eastern half of the country is the main culprit, according to the National Weather Service.

The dome is like a giant atmospheric lid of hot air near the surface, suppressing clouds and storms, and letting the sun crank temps higher.

The result is a muggy, sweat-soaked stretch of weather that could send “feels-like” temperatures soaring into the triple digits in some spots.

North Jersey is staring down some especially intense early-season heat records too.

Forecast models around Teterboro Airport show temperatures could spike to 93 degrees on Tuesday, according to NJ.com. The record high for that date in Newark is 98 degrees, also set back in 1962.

Forecasts for Wednesday still call for temperatures near 90 degrees across North Jersey, though scattered showers and storms may begin creeping into the picture as the cold front — and relief — approaches, knocking temperatures back down to finally break the hot and humid grip.

Forecasters say the hottest conditions are expected from the Mid-Atlantic into the Carolinas, where highs throughout the entire area could rocket into the low- to mid-90s — enough to flirt with daily record temperatures before cooler air finally pushes in by Thursday.

A late-week cold front will finally deliver relief.

“That’s going to come quickly, too, so the heat will be a shock coming in and going out,” said Erickson.