With Arctic air spilling into the region, the week leading up to daylight-saving time has started out with frigid temperatures on Long Island -- about 20 degrees below normal, forecasters say.

Thanks to a northerly wind, Monday was brutally cold, said Tim Morrin of the National Weather Service's Upton office.

The high reached the mid-20s Monday, and there's more of that to come on Tuesday, forecasters said.

Average monthly normals for March are a high of 45.7 degrees and a low of 31.4, according to weather service statistics.

As for low temperatures, 9 degrees is expected Tuesday at Long Island MacArthur Airport in Ronkonkoma, where the record is 5, set in 2009, said Joey Picca, also a meteorologist in Upton.

Morrin said there also is a slight chance for snow Thursday into Friday morning, but early indications are that the brunt of that system also will move well south and east of Long Island, he said.

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Temperatures start to moderate Wednesday, with highs in the mid-30s -- and mid- to upper 30s for Thursday, he said.

In keeping with a slight "warming trend," look for Friday's and Saturday's highs to be about 40 degrees, though still below the norm for this time of year, he said.

By Sunday, when clocks spring ahead an hour, the temperature should be "within a couple of degrees" of the norm for the day, which is 46 degrees, said Bill Korbel, News 12 Long Island meteorologist. That may not be warm, he said, but at least it won't be bone-chillingly cold.


With Patricia Kitchen