The coldest air of the season so far will settle across the United States this weekend, producing a blanket of snow in the Mid-Atlantic and Northeast on Sunday, and bringing below-freezing temperatures with dangerously blustery winds to most of the country.

Facing what was likely to be one of the coldest inaugurations in decades, President-elect Donald J. Trump on Friday said he would move Monday’s swearing-in ceremony indoors.

“The cold air is coming directly from the Arctic and will surge south through Canada and into the U.S. over the weekend and into early next week,” said Alex Lamers, a meteorologist with the National Weather Service’s Weather Prediction Center.

Chilly temperatures in January are not unusual, but these conditions are likely to be abnormally cold. The cold will settle across the country slowly, starting in the Upper Midwest on Saturday, plunging temperatures more than 30 to 40 degrees from earlier this week, before moving toward the southern and eastern coasts Sunday.

As the cold air trudges across the country, a storm system off the East Coast could combine to bring a burst of wintry weather Sunday. There is a moderate likelihood of three to six inches of snow falling from Washington D.C. through New York City and up to Boston.