2008–09 North American winter

The 2008–09 North American winter was quite variable in terms of winter weather, influenced by neutral ENSO conditions. The Weather Prediction Center (WPC) tracked a total of 19 significant winter weather events during the season. A large portion of the northern half of the United States saw large amounts of snowfall, with several high-impact winter storms occurring. 10 events were rated on the Regional Snowfall Index (RSI), although only one managed to be rated above a Category 3 "Major" ranking, which was a significant and crippling late-season blizzard in March that affected the central U.S. Other significant events included crippling ice storms in the Northeast and Ohio Valley in December and January respectively, cold outbreaks in mid-January and a major nor'easter that affected the Eastern U.S. at the end of February into the first week of March. Collectively, the winter storms and related weather resulted in 80 deaths during the season and caused an estimated $3.62 billion (2009 USD) in damages, most of which came from the two ice storms in December and January.

While there is no well-agreed-upon date used to indicate the start of winter in the Northern Hemisphere, there are two definitions of winter which may be used. Based on the astronomical definition, winter begins at the winter solstice, which in 2008 occurred on December 21, and ends at the March equinox, which in 2009 occurred on March 20. Based on the meteorological definition, the first day of winter is December 1 and the last day February 28. Both definitions involve a period of approximately three months, with some variability.