After a brief flirtation with normality during the weekend, the weather in Christmas week evidently is going to feel a lot like Easter.
White Christmas? Santa's sleigh had better have wheels.
Forecasters say the highs Christmas Eve should reach the mid- to upper 60s, about normal for the latter half of April.
In the meantime, an impressive streak is about to end. Saturday will be the first day of below-normal temperatures in 24 days.
Through Thursday, official temperatures in Philadelphia were running almost 12 degrees above normal this month, which almost certainly will become the warmest December on record.
Not that Philly has had exclusive rights. The warm virus has gripped the East, with temperatures radically above averages in the likes of Washington, New York City, Boston, and Burlington, Vt.
What's more, the government's Climate Prediction Center said in its outlook, updated this week, odds are for warmth through March.
Key indicators - low pressure favoring cold in the West, the mirror opposite in the East - show above-normal temperatures and an active Gulf Coast-East Coast storm track right through the winter.
The reasoning behind the forecast discussion probably could be summed up in one Spanish phrase: El Niño.
The climate center scientists are confident that the extreme warming of surface waters in a vast area of the tropical Pacific - about five degrees above normal in the key zone - has peaked.
Likewise, they are confident that significant warming will persist into spring, and that the warming of the overlying air has some predictable effects on the planet's circulation - though many, many more that are unpredictable.
It almost certainly will be a rather unpleasant winter for some snowbirds in Florida, where it will be generally damp and cool, and New Jersey beaches will likely lose some sand from a potential harvest of nor'easters.
As for snow, despite the warmth, don't rule it out. Strong coastal storms could draw in cold air, assuming any is available to be mined.
The last three mega-El Niños coincided with three of the region's strangest winters.
The winter of 1972-73 remains the only snowless one on record. February 1983 was crowned by a paralyzing blizzard that left what was then a record snowfall in Philadelphia and temporarily entombed motorists in the Lincoln Tunnel.
And for the entire winter of 1997-98, less than an inch of snow was measured in Philadelphia, despite a robust sequence of coastal storms.
In the meantime, savor those low heating bills - energy demands have been about two-thirds of normal, according to government figures - and keep watch for outerwear sales.