It's an El Niño season, which means winter's worst usually holds off for a few weeks in the usually icy Northeast. But this is ridiculous.
It's so hot that golfers are teeing off in shorts — in Buffalo, New York.
It's so hot that a guy got famous for running without his shirt — in Chicago.
Guy running shirtless in Chicago announces he’s single, goes viralDec. 15, 201500:52
It's so hot that a guy went jet-skiing — on Lake Erie. Sure, he wore a Grinch T-shirt and a Santa hat, but still.
Related: Why's It So Warm? Thank the Polar Vortex
There's a strong polar vortex — an arctic cyclone of extremely cold air high up in the atmosphere — keeping cold air that should have swept south penned up north of the border, making for decidedly un-December-like conditions.
Record Snow Batters the West, Record Highs Heat up the EastDec. 15, 201501:38
According to meteorologist Kathryn Prociv and our colleagues at The Weather Channel, with just 10 days till Christmas:
- New York City (64 degrees — 22 degrees above the average for Dec. 15) was warmer Tuesday than Phoenix (54).
- Boston (58) was warmer Tuesday than Las Vegas (50).
- Washington, D.C. (62), was about the same temperature Tuesday as Los Angeles (60).
- Forget lake effect snow. Syracuse and Binghamton, New York, hit 66 and 61 degrees, respectively, on Monday. It goes without saying those are records.
- Louisville, Kentucky, recorded its third straight 70-degree-plus day Monday. That's never happened before in December.
- International Falls, Minnesota — the synonym of choice for "Good Lord, it's cold!" — hasn't dropped below 16 degrees all month. It's December average low is usually 1 degree.
- Providence, Rhode, Island, set a record high Monday night at 9:58 p.m. Four hours later, it set a record high for Tuesday morning.
- Green Bay, Wisconsin, got its the second-biggest rainstorm of the year on Monday. That's because it was too warm for snow.
"We've had so many places experiencing warmer-than-average temperatures,” said Danielle Banks, a meteorologist for The Weather Channel.
But cold air will finally return by the weekend — sending temperatures only to where they should have been all along, she said.