2025–26 North American winter

The 2025–26 North American winter featured extreme contrasts across North America; being consistently frigid and wintry across the eastern half, particularly in the Northeastern United States – the most impactful since the 2020–21 winter season, while the western half of the continent experienced record warmth and lack of wintry precipitation. The Weather Prediction Center (WPC) has tracked 17 significant winter weather events, with 6 winter storms being rated on the Regional Snowfall Index (RSI), with 2 attaining a ranking of "Major" (Category 3+). The winter season began early with the remnants of Typhoon Halong affecting the U.S. state of Alaska in mid-October. The prevalent pattern during the winter, beginning in December, featured a dip in the jet stream and polar vortex over the eastern half of the country. This continued into January despite a brief warm-up, evolving into a prolonged and extensive cold wave that lasted into mid-February; with the most significant and damaging event of the season occurring at the end of the month with a widespread and devastating Category 3 winter storm that affected almost the entire continent. Significant events continued into February, with the the heaviest winter storm in the Carolinas in decades at the start of the month, and a historic and severe Category 3 blizzard that affected the Northeast in the second half of the month. Collectively, the winter weather events this season have killed at least 250 people – the deadliest since the 2020–21 winter season, and together causing an estimated $5.505 billion in damages.

The persistent pattern during the winter also contributed to other significant events during the season, including those ranked on the RSI, included a pair of two RSI-rated winter storms that disrupted post-US Thanksgiving travel across the continent, and a disruptive Category 2 winter storm in mid-December that brought some of the largest snowfall accumulations to the Mid-Atlantic/I-95 corridor in several years. Additionally, a large storm complex produced extremely high wind gusts across the western U.S. following the previous storm. Separately, the lack of winter storms tracking through the Rocky Mountains region has led to one of the worst snowpack seasons there to date, due to persistent ridging of high pressure, above-average temperatures and unfavorable storm tracks; the city of Salt Lake City, Utah experienced its least snowy winter on record as a result. Like the previous winter, a weak La Niña was expected to influence weather patterns across the North American continent during the season.

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 2025 occurred on December 21, and ends at the March equinox, which in 2026 will occur 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.