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NOAA winter weather collage.Dec. 22, 2003 — Across the United States people have pulled out their shovels and snow blowers as winter weather storms returned for another season. Winter is here, and it began right on schedule–December 1. That’s right. That’s the official start of the winter season and how official weather records are kept. Weather-wise, winter does not begin on December 22, as many calendars claim.

What most people usually refer to as winter is what’s really known as astronomical winter. This type of winter starts at the winter solstice, which this year occurs December 22, when the sun’s angle and its heating capacity is at a minimum in the northern hemisphere. It ends at the vernal equinox about March 21.

"What many people don't know is that there is another kind of winter called meteorological winter" said Steve Kuhl, warning coordination meteorologist with the NOAA National Weather Service in Washington, D.C. "The further north you live, the earlier it starts."

For weather watchers, meteorological winter is the three month period of December, January, and February. In northern locations, meteorological winter begins long before the winter solstice. Meteorological winter is based on sensible weather, like when snow and ice fall, while astronomical winter is based on the position of the Earth in its orbit around the sun. The start of astronomical winter is the same everywhere, but the start of meteorological winter changes depending on how far north you live.

So, don’t think winter arrived December 22. It’s been here. It started right on time on December 1. Just ask the millions of people across the USA who’ve donned their ski pants and battled old man winter.

NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation’s coastal and marine resources. NOAA is part of the U.S. Department of Commerce.

Relevant Web Sites
NOAA Winter Weather Safety and Awareness

NOAA National Weather Service

NOAA Storm Watch

Media Contact:
Susan Weaver, NOAA National Weather Service, (301) 713-0622