When Does Winter Officially Start 2025 Uk. Does the solstice mark the start of winter? Winter in the uk starts in december and runs until the end of march.

The astronomical calendar, which is based on the natural rotation of the earth around the sun, holds that winter starts on the day of the winter solstice, december 22, and ends on march 20. So, what is the winter solstice, and why does it happen?