The Big Freeze is headed back.

A polar vortex will send a bone-chilling blast of frigid air toward the Big Apple and rest of the Northeast by mid-week, while threatening to bring record-setting low temps in the Midwest.

“It is going to bring in the coldest air mass of the season so far,” AccuWeather senior meteorologist Dave Dombeck told The Post on Monday.

On Tuesday, temperatures are set to rise above 40 — briefly. Then they drop. And drop.

“With the cold will also come wintry weather,” said Dombeck, who added that New York City could see a coating to an inch of snow Tuesday night.

By Wednesday, temps will hit a high of only 28 degrees, while a low of 5 degrees is predicted.

Temperatures in the city Thursday are set to reach a teeth-chattering high of 14 degrees and a low of 8 degrees.

The arctic blast will put the real-feel temperature at negative 1 degree on Thursday, according to Accuweather.

“It will feel pretty nasty,” Dombeck said.

Temperatures are slated to remain below freezing through Friday and Saturday.

Mayor Bill de Blasio’s office tweeted a warning Monday for New Yorkers to “brace” themselves and “please look out for your vulnerable neighbors during these frigid cold days.”

Meanwhile, even more extreme and dangerous cold is expected this week from the Northern Plains through the Great Lakes, with lows in the negative 30s and 40s and wind chills as low as the negative 60s from Wednesday through Thursday.

The polar vortex — bringing what AccuWeather called “the coldest weather in years” — is set to extend from the Dakotas through New England, with Chicago expecting temps to dip as low as negative 25 degrees overnight Tuesday into Wednesday, forecasts show.

It would be the first time the Windy City has seen temps that low since the mid-1980s, according to the weather service.

“I cannot stress how dangerously cold it will be,” AccuWeather senior meteorologist Mike Doll said. “An entire generation has gone by without experiencing this type of cold in the Chicago area.”

Real-feel temperatures could drop under 40 below zero from Fargo, ND, to Minneapolis and Chicago and will be below zero continuously for 48 to 72 hours, according to AccuWeather.

The weather service noted that the “harshest conditions” are anticipated from North Dakota to northern Illinois.

“In addition to the risks of frostbite and hypothermia, residents will be faced with high heating costs and the potential for frozen and bursting water pipes, dead car batteries and school closures,” AccuWeather said, adding, “The cold can be life-threatening for any person or animal without a proper way to stay warm.”