2014–15 North American winter

2014–15 North American winter

A temperature map of the frigid conditions in North America on November 13, 2014
Astronomical winter	December 21 – March 21
Meteorological winter	December 1 – February 28
2013–14 2014–15 2015–16

The 2014–15 North American winter refers to winter as it occurred across the continent from late 2014 through early 2015. 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 2014 occurred on December 21, and ends at the March equinox, which in 2015 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.

While both the meteorological and astronomical definitions of winter involve the onset of winter occurring in December, many places in North America experienced their first wintry weather during mid November. A period of below-average temperatures affected much of the contiguous United States, and several records were broken. An early trace of snowfall was recorded in Arkansas. There were greater accumulations of snow across parts of Oklahoma as well. A quasi-permanent phenomenon referred to as the polar vortex may have been partly responsible for the cold weather. Temperatures in much of the United States dropped 15 to 35 °F (8.3 to 19 °C) below average by November 19 following a southward "dip" of the polar vortex into the eastern two-thirds of the country. The effects of this dip were widespread, bringing about temperatures as low as 28 °F (−2 °C) in Pensacola, Florida. Following a significant snowstorm there, Buffalo, New York received several feet of snow from November 17–21. During the 2014–15 winter season, Boston broke its all-time official seasonal 107.6-inch (2.73-meter) snowfall record from the winter of 1995–96, with a total snowfall record of 108.6 inches (2.76 m) as of March 15, 2015.

Many records for snowfall and temperature were broken, many for the month of February, with every state east of the Mississippi River being colder than average, some for the entire winter. However, this meteorological winter was the 19th-warmest of the past 120 winters over the lower 48 states, largely due to persistent warm weather in the West.