2022–23 North American winter

The 2022–23 North American winter was quite warm for the eastern half of North America, with much of the Eastern United States experiencing one of their warmest and least snowy winters on record. Despite this, numerous significant events still occurred, including a severe lake-effect winter storm across the Great Lakes region in mid-November, a cold wave bringing extremely cold temperatures to the Northeast in early-February, and several tornado outbreaks throughout the winter. However, most of the winter's damage and fatalities were due to a crippling and historic winter storm that wreaked havoc across the majority of the United States and parts of Canada in late-December. Additionally, the Western United States was colder than usual in contrast to the east, with a series of atmospheric rivers through December to March bringing widespread flooding in California and record amounts of snow across the region. During the winter, five storms have been ranked on the Regional Snowfall Index (RSI), two of which have attained the “Major” category. Similar to the previous two winters, a La Niña was expected to influence weather patterns across the continent.

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 2022 occurred on December 21, and ends at the March equinox, which in 2023 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. Winter is often defined by meteorologists to be the three calendar months with the lowest average temperatures. Since both definitions span the calendar year, it is possible to have a winter storm spanning two different years.