2013–14 North American winter

The 2013–14 North American winter was extremely active, deadly, record-breaking and bitterly cold for the United States and North America as a whole, due in part to the collapse of the polar vortex in November 2013, which allowed very cold air to travel down into the United States, leading to an extended period of very cold temperatures. The pattern continued mostly uninterrupted throughout the winter and numerous significant winter storms affected the Eastern United States. The Weather Prediction Center (WPC) tracked a total of 27 significant winter storms from November to May, underlining the hyperactivity during the winter months. Several of these events included a massive storm complex that affected most of the country and Canada before Christmas, two separate blizzards that affected the Northeast during the month of January with up to 1 foot (12 in; 30 cm) of snow, and a rare Gulf Coast winter storm. The most notable of these events ended up being a powerful winter storm and nor’easter that dumped ice and snow in the Southeastern United States and the Northeastern United States in mid-February. Most of the cold weather abated by the end of March, though a few winter storms did affect the Western United States towards the end of the winter.

Due to the polar vortex phenomenon, a majority of the United States had one of their coldest and snowiest years on record, particularly in cities east of the Mississippi River, as a result of several storms taking a favorable path through the Northeast and along the coastline, supplied by plentiful cold air. The city of Detroit ended up having its snowiest winter on record. Additionally, arctic air plunged south enough that areas along the Gulf Coast of the United States experienced wintry precipitation, which is a rarity and left many citizens unprepared there as a result. Collectively, the wintry weather resulted in approximately 134 deaths in total across the continent, with damage estimated to be over US$5 billion (2014 USD).

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 2013 occurred on December 21, and ends at the March equinox, which in 2014 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.