When does Winter Start and End in the U.S. in 2025?

When does winter start in the U.S.? Every year, you look forward to the season, whether you can't wait for the first snowfall or dread the long, cold nights. People in the United States may find it surprisingly hard to figure out the official start and end dates because there isn't just one answer! It depends on which calendar you use: the astronomical or the meteorological.

Knowing when winter starts is more than just a fun fact; it's important for planning everything from holiday travel (think about the weather on Thanksgiving, leading up to the cold) to knowing when to put on your heavy coat. Did you know that recent climate trends, according to the National Weather Service (NWS), show a tendency for more warm La Niña winters in the U.S. since the early 1990s? 

Regardless of the actual temperatures, the official calendar dates provide the necessary structure for what season we are in. Let's break down the facts for winter in the US in 2025!

When does Winter Start in the United States?

The starting point of winter in the US depends entirely on the system you use: Astronomical or Meteorological. Both are valid and used by different groups of people for different purposes.

Astronomical Winter

Astronomical winter is based on the Earth's position relative to the Sun. It begins with the Winter Solstice, which is the moment the North Pole is tilted farthest away from the Sun, resulting in the shortest day of the year.

For the Northern Hemisphere, which includes the entire United States, the start of astronomical winter in 2025 is:

• Start Date: Sunday, December 21, 2025

• Start Time: 4:21 AM Eastern Standard Time (EST)

The astronomical definition is a geographical fact tied to celestial mechanics. It is the most common answer to the question, When does winter start.

NOAA’s National Weather Service Winter Outlook has been released.

This outlook shows the likely temperature and precipitation the U.S. could experience during meteorological winter (December 1, 2025 through February 28, 2026) and drought conditions through January 31, 2026.… pic.twitter.com/wM6eQBDDoq

— National Weather Service (@NWS) October 16, 2025

Meteorological Winter

Meteorological winter is based on the annual temperature cycle and is used by meteorologists and climatologists to calculate seasonal statistics more easily. It breaks the seasons into three-month periods that align with the Gregorian calendar. This definition is more representative of the coldest period of the year and the time when we generally see the most snow in the US.

• Start Date: Monday, December 1, 2025

• End Date: Saturday, February 28, 2026

The National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center and other groups like this one like the meteorological method because it lets them make year-after-year comparisons of monthly and seasonal weather data that are always the same.

Check Out - First Snowfall in the US 2025: Know When and Where Winters Will Appear First

List of Winter Months in the USA

The following table details both the astronomical and meteorological periods that define the season in the United States:

Must Read: Seasons of the Year in the United States: What Season is It in the US Now?

When does Winter End in the US? 

There are two meanings for the start of the season, and there are also two meanings for the end. This is important for figuring out when winter is officially over. The end date for the United States depends on the definition used:

• Astronomical End:  The Vernal Equinox, or Spring Equinox, marks the end of the season. It falls on Friday, March 20, 2026. This is when the Sun crosses the celestial equator, which means that day and night are about the same length.

• Meteorological End:  The season ends on Saturday, February 28, 2026, which is the last day of the coldest three-month period.

Also Read : How Many Federal Holidays does November 2025 have in the U.S? Check List

Many cultures have celebrated the Winter Solstice, which marks the start of astronomical winter, throughout history. People believe that Stonehenge and other ancient monuments were built to keep track of the Sun's yearly journey and mark this important turning point, the day when the hours of daylight start to get longer.