Winter Equinox 2025 Uk Dates. In 2025, these are the astronomical dates and times for the start of each season: It falls on december 21st or 22nd in the northern hemisphere and june 20th or 21st in the southern hemisphere.

The autumnal equinox occurs in september, and in the northern hemisphere this date marks the end of summer and beginning of autumn. This year autumn begins on 23 september 2023 and ends on 22 december 2023.