Winter 2025 starts on Sunday, December 21, 2025 in the Northern Hemisphere, with the winter solstice marking the official first day.

Key dates

  • Astronomical winter 2025 (Northern Hemisphere): starts Sunday, December 21, 2025, at about 10:03 a.m. EST / 15:03 UTC, when the winter solstice occurs.
  • Meteorological winter 2025–26 : runs from December 1, 2025, to February 28, 2026, based on the three coldest calendar months.
  • Many calendars and almanacs list “First day of winter 2025” as December 21, 2025 , aligning with the solstice.

Quick scoop: why two “starts”?

  • Astronomical winter uses the position of the Sun; it begins at the solstice, the shortest day of the year in the Northern Hemisphere.
  • Meteorological winter is a climate/statistical convention starting December 1 for easier comparison of yearly weather data.

If you’re in the Southern Hemisphere

  • In places like Australia or South Africa, “winter 2025” usually runs from June 1 to August 31 using meteorological seasons.
  • Astronomically there, winter begins around the June solstice (June 20–22), not in December.

Information gathered from public forums or data available on the internet and portrayed here.