Hawthorn berries in a frost. Photo Galina N

When does winter start?

The day in our calendar that marks the first day of winter usually refers to the astronomical seasons which are a result of the Earth's axis and orbit around the Sun.

This year, astronomical winter begins on 22 December 2019 and ends on 20 March 2020.

For upcoming years, the dates for astronomical winter will be;

Year Winter Starts Winter Ends
Winter 2019

Sunday, 22 December 2019

Friday, 20 March 2020

Winter 2020 Monday, 21 December 2020   

Saturday, 20 March 2021

Winter 2021 Tuesday, 21 December 2021   

Sunday, 20 March 2022

Winter 2022 Wednesday, 21 December 2022   

Monday, 20 March 2023

Winter 2023 Friday, 22 December 2023  

Wednesday, 20 March 2024

Winter 2024 Saturday, 21 December 2024    

Thursday, 20 March 2025

The astronomical calendar determines the seasons due to the 23.5 degrees of tilt of the Earth's rotational axis in relation to its orbit around the Sun. Both Equinoxes and Solstices are related to the Earth's orbit around the Sun. However, the dates of the Equinox and Solstice aren't fixed due to the Earth's elliptical orbit of the Sun.

Meteorological winter

However, at the Met Office, we often use a meteorological definition of the seasons. By the meteorological calendar, the first day of winter is always 1 December; ending on 28 (or 29 during a Leap Year) February. 

Meteorological seasons consist of splitting the seasons into four periods made up of three months each. These seasons are split to coincide with our Gregorian calendar, making it easier for meteorological observing and forecasting to compare seasonal and monthly statistics. 

The seasons are defined as spring (March, April, May), summer (June, July, August), autumn (September, October, November) and winter (December, January, February).