On Sunday, the temperature in New York City’s Central Park hit 67 degrees—the warmest Dec. 13 since 1923. Manhattanites practiced yoga outdoors and ice-skated in short sleeves. The Yuletide heat wave was even more impressive elsewhere, breaking some of the longest-standing American temperature records, some dating back 142 years. Greenwood, Mississippi, hit 83 degrees. Even the self-described “icebox of America,” International Falls, Minnesota, has had a mild start to the winter season: The high temperature there has dipped below the freezing mark only once so far this month—about 20 degrees warmer than a typical first half of December.
What the heck is going on?
To be clear: Global warming wasn’t primarily to blame/thank for this weekend’s ridiculously warm weather. A record-breaking El Niño has shunted the jet stream far to the north, paving the way for warm air to shatter records. The lack of snow so far—that may change later on this winter—has also helped keep things warmer: Without snow on the ground, the feeble December sun can warm things up much more efficiently. Third on the list, bumping up temperatures by perhaps a couple of degrees, is global warming. (Though, recent science suggests super-strong El Niños like this one might become more common in the coming decades.) Blaming an exceptionally warm December day entirely on global warming is just as misplaced as senators seeking to use a snowball as proof against it. Climate change made this weekend’s warmth more likely, but it wasn’t the main driving force.
What happens this winter will largely be up to El Niño, which has reached its peak strength in the Pacific Ocean and will soon begin to manifest itself even more strongly in U.S. weather. Judging from the latest weather model outlooks, warmth in the East isn’t going away anytime soon—we’ll have above average temperatures at least through mid-January. Monday morning’s weather models are hinting that East Coast temperatures in the 60s (and maybe even 70s) are possible again on Christmas Day. With more record-breaking likely to ensue, there’s now a zero percent chance of a White Christmas this year from Washington, D.C., to Boston.
One of the most impressive Christmas Eve temperature anomaly maps I've ever seen at this lead time. Record Warmth. pic.twitter.com/zsZQMcYTLp— Michael Ventrice (@MJVentrice) December 14, 2015
With that kind of forecast, it’s time to start planning a post-presents picnic on Christmas Day. And we should enjoy it! An El Niño like this doesn’t come along often. Though global warming will boost temperatures even more in future winters, this month’s crazy warm weather would probably have happened almost exactly the same way without it.