Winter Solstice 2025 Us. When is the winter solstice? For most people, the winter solstice is an astronomical event that tells them they have reached the winter season and the time of the year when nights are longer than days.
The winter solstice, which marks the first day of winter 2025, occurs on sunday, december 21, 2025, 10:03 a.m. So, what is the winter solstice and why does it happen?