It could be nearly 70 degrees in Philly this weekend. What happened to January?

While the winter solstice arrived almost three weeks ago, this weekend it will feel more like three weeks after the spring equinox, with record highs possible Saturday and temperatures on Sunday flirting with 70 degrees and a 129-year-old record.

Perhaps more impressive is that the official forecast “low” for Sunday morning, 59, would be the normal low for a June 1.

Saturday’s high will be close to the record for the date, 66, set in 1875. Sunday’s current record is a toastier 72, dating all the way back to 1890.

In other winters, this might qualify as a “January thaw.” Except right now, there’s not much out there to thaw.

Since the solstice occurred at 11:19 p.m. on Dec. 21, Philadelphia has had exactly one day of below-normal temperatures, and that was Thursday.

“It’s one and done,” said Dave Dombek, a meteorologist with AccuWeather Inc. Temperatures were due to approach 50 on Friday, “and it might be more than a week before we get a below -normal day.” Highs through the workweek next week are expected to be 50 or better.

» READ MORE: Winter forecast has mild outlook for Philly and most of the nation, continuing warming trend

What’s going on out there? One place to look for a short-term clue is to the west, Dombek said.

A potent winter storm is likely to lacquer some of Chicago’s suburbs with ice during the weekend, while the Windy City itself will be close to the rain/snow line — coincidentally, similar to where Philadelphia often finds itself during nor’easters.

Philadelphia fortuitously will be well to the east of that Midwest storm and will experience the warming, southerly winds that are part of the counterclockwise circulation around the centers of low pressure. Records also could fall in Boston, New York, and elsewhere in the East Saturday and Sunday.

The overall pattern this season has been for the larger storms to cut to the west of Philadelphia, and that’s related to storm-repelling high pressure over the Southeast, which also has kept nor’easters at bay, he said.

Meanwhile, a circulation pattern over the North Atlantic has been unfavorable for significant snows, and fast-moving upper air winds have kept any prolonged cold air from building.

“It’s a very transient pattern where systems keep zipping along,” Dombek said. “There’s no blocking.”

Through Thursday, temperatures in Philadelphia were averaging about 6 degrees above normal, and that likely will climb to double digits during the weekend.

The government’s long-range outlook favors above-normal temperatures for the period that ends Jan. 19. But beyond that, it’s pretty much anyone’s guess.

In the meantime, happy April. And though it might be a tad warm for the average polar bear, the annual Wildwood Polar Bear Plunge benefitting the Special Olympics will be held Saturday, in which otherwise sane human beings will immerse themselves in the Atlantic Ocean.

As for the water temperature, at 42, it’s also above normal, by about 5 degrees.