Winter Dark Sheds Light on What Makes Coming Days Cold

Winter will officially begin at 6:03 p.m. New York time on Dec. 21.

That marks the point at which the least amount of sun falls across the northern half of the globe, and dark means cold.

Obviously with daylight pretty much absent in the northern latitudes, the days are getting very short and that is the nursery for our polar and arctic air masses, said Michael Schlacter, a meteorologist with Weather 2000 Inc. in New York.

In New York City, Dec. 21 will have 9 hours, 15 minutes and 16 seconds of daylight, according to Timeanddate.com. When the new work week begins, things will already be looking up because daylight will have increased by a second.

In Boston, the daylight on the 21st will be about 10 minutes shorter than in New York, while Chicago will have about seven minutes less. As depressing is that sounds to people who like sunshine, Torontos daylight only lasts 8 hours, 55 minutes and 43 seconds, which is still more than an hour of what will fall on London.

Well refrain from using the colloquial shortest day of the year because even Dec. 21 will have 24 hours.

The cold will wax and wane through the course of the winter for a variety of reasons. One is that after truly frigid air drops out of the Arctic into the more temperate latitudes of North America, it takes time to rebuild the supply.

Schlacter said for the U.S. to have a winter that lasts, cold snaps have to be interspersed with milder periods.

You dont want every week to be freezing cold if you want to have a long winter, he said. You have to recharge that Canadian freezer.

Snow on the ground can also influence temperatures. The suns energy is used up melting the frozen crust rather than heating the air.

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Winter Dark Sheds Light on What Makes Coming Days Cold