When Does Winter Start 2025. The longest day of 2025, also known as the summer solstice, is friday, june 20. Starts on december 21, 2025, at 4:21 am and lasts until march 20, 2026, at 5:01 am (93 days) the times correspond to the eastern time (et) time zone and will vary in different states.
Winter solstice 2025 (beginning of astronomical winter) on the day of the winter (december) solstice, the sun passes through the southernmost point of the ecliptic, that is, as far as. Winter begins with the winter solstice, sunday, december 21, 2025, 10:03.
