Philly is forecast to have its coldest Christmas in three decades

Bundle up, Philadelphia. After rain sweeps across the region Thursday, temperatures are expected to plummet well below freezing heading into the holiday weekend.

That means Sunday will likely be the coldest Christmas Day in three decades. The last time Philadelphia had a Christmas this frigid, President George H.W. Bush was in the White House, a comedy show called Seinfeld had recently premiered on NBC, and Billy Joel’s “We Didn’t Start the Fire” was the No. 1 song in the country.

That year was 1989. Fast-forward to 2022, Philadelphians should brace for a high temperature of 22 degrees Saturday and Christmas Day temperatures not budging past 25. Overnight temperatures are forecast to drop into the teens.

While the National Weather Service in Mount Holly guaranteed the atypical chill this weekend, it says there’s little chance of a white Christmas, which some had gotten their hopes up for just last week.

High temperatures in Philadelphia on Dec. 25 historically average about 41 degrees. The last time the region had a white Christmas was in 2009, when more than three inches of snow fell.

“It’s extremely unlikely this year,” said Joe DeSilva, a meteorologist with the weather service. “There may be a quick burst of snow on Friday afternoon with the passing of the [cold] front, but no accumulations expected.”

The temperatures may be a shock for a region that had its second-warmest December on record last year. Temperatures on Christmas Day in 2021 didn’t drop below 50, with warm, wet weather.

A strong low-pressure system is responsible for this year’s weather reversal, coming in from the Great Lakes region and mixing with a high-pressure system from the north-central United States.

“It’s going to cause a cold Arctic air mass to plunge southward and basically sit over our region throughout the weekend,” DeSilva said.

The system will kick off with rain, expected to begin late Thursday morning and lasting through Friday afternoon. Temperatures should be mild leading up to the holiday plunge, with Thursday’s and Friday’s highs in the low 50s before the Arctic air moves in Friday evening.

Philadelphia could see an inch and a half to two inches of rain, DeSilva said. There’s no risk of flooding in the immediate region, he said, but areas near the Poconos and Lehigh Valley, as well as northwestern New Jersey, should be on alert for potential flooding.

The cold is expected to last through Monday, before temperatures are forecast to creep back up to highs in the mid-30s Tuesday and Wednesday.