What to say about this superheated December …
That the monthly average, 48.5 degrees, registered 12.7 degrees above normal — that’s as of day-end Wednesday.
That Long Island MacArthur Airport, for which records have been kept since 1984, saw a record number of days in the 60s — that would be nine, compared to the previous record of six seen in December 1998, according to the National Weather Service office in Upton.
News 12 Long Island meteorologist Rich Hoffman on Thursday morning pointed out that every day in the month came in at above normal, with the last one expected to do so, too.
With a high of 64 and low of 55, Christmas Eve day registered an average temperature that was 27 degrees above normal. Make that a 25-degree departure for Christmas Day.
The month, too, was flooded with daily records for highs with 11, and warmest lows with 12, said Faye Barthold, weather service meteorologist in Upton.
With the final day of the year seeing a high of 50, with around 37 expected to be the low, this December will certainly be crowned the warmest on record for the airport since the weather service started keeping records, she said. The soon-to-be previous record monthly average was 41.2 degrees seen in both 1984 and 2001.
“Pretty impressive,” Barthold said.
Such warmer than normal Decembers are not uncommon for Long Island during a strong El Niño, a climate pattern that starts with a warming of the Pacific that affects weather worldwide, said Jessica Spaccio, climatologist with the Northeast Regional Climate Center based at Cornell.
El Niño, with this year’s especially strong, keeps the jet stream — a sort of superhighway of westerly winds — to the north, which holds colder temperatures at bay and allows warm, moist air up from the south.
Climate change is not a driver of the above-normal warmth, Spaccio said, but could make already high temperatures just a tad higher.
Still, the pattern is about to take a turn for the cold, with the weather service and others saying to get ready for a higher probability for normal temperatures — and possibly below normal temperatures — for the beginning of January.
For the first week of the month, Hoffman said, highs average out to close to 40 and lows near 24.
New Year’s Day, he said, is forecast to bring sun, clouds, and breezy conditions, with highs near 44.