When Does Winter Begin 2025. Winter 2025 starts on sunday, december 21st in the northern hemisphere, with the first day of winter being the shortest daylight day of the year with the earth's axis having reached its furthest tilt away from the sun and begins to change directiion back. For the year 2023 the meteorological winter will begin on friday, december 1, 2023 and will end on thursday, february 29, 2024.

This marks the beginning of the astronomical winter,. What day does summer start?