Winter Begins 2025 Date. In 2025, it occurs on december 21 at 2:49 pm. This year the winter solstice in the northern hemisphere is on 21 december and therefore our astronomical winter begins on that date.
This is when the winter solstice, or the shortest day of the year, occurs. 21, 2025, with the winter solstice at 4:21 a.m.