Mother Nature is a Grinch. Snow and rain are expected to create challenging travel conditions across much of the U.S. ahead of the holiday, followed by Arctic temperatures for Christmas weekend.

A cold front headed east from the Rockies is expected to blow snow into the Midwest and Ohio Valley around midweek, just in time for the official start of winter on Dec. 21. The East Coast can expect icy rain and wind, the National Weather Service said.

As soon as the precipitation stops, a powerful surge of cold Arctic air is going to sweep in for the weekend, according to the forecast.

Temperatures across the Central and Eastern U.S. and the South will be anywhere from 20 to 30 degrees colder than usual through Christmas Day, said Zack Taylor, a National Weather Service meteorologist.

A satellite image of the Northeastern U.S. on Sunday.

Photo: NOAA

“We’re going to see some of the coldest temperatures we’ve seen so far this season, and it’s potentially shaping up to be one of the coldest Christmas Days we’ve had in a while, at least across the Eastern two-thirds of the country,” he said Sunday.

Strong winds will add to the misery, especially in the Great Lakes region, according to Mr. Taylor.

“We’ll probably have a large area of potential wind chill advisories,” he said.

The storm system expected to move eastward from the Northern Rockies about midweek will dump accumulating snow on the Midwest, Ohio Valley and Great Lakes region by Thursday, if not earlier. It is still too early to predict how much, but it will be “more than a dusting,” said Mr. Taylor.

The East Coast won’t have to grapple with snow, but it will contend with potentially heavy rainfall and winds, making for messy travel days, said Mr. Taylor.

The storm will likely end by Friday. However, the Arctic blast on its heels is bringing freezing temperatures to the north and colder-than-usual ones to the south, he said. Not even Florida can escape the sudden drop in temperatures.

“Anyone east of the Rockies is going to have a cold Christmas,” Mr. Taylor said.

Write to Ginger Adams Otis at Ginger.AdamsOtis@wsj.com