Shortest Day Of 2024 Usa. In 2024, it falls on saturday, december 21, at 4:21 a.m. Winter solstice is the shortest day of year, longest night of the year and the official first day of winter in the northern hemisphere.

Learn how the seasons are defined by astronomical and meteorological start dates, and why they vary over time. Winter 2024 starts on saturday, 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.