December 21st Brings the Annual Winter Solstice and Year's Shortest Daylight

The winter solstice occurring December 21st marks the year's shortest day and longest night in the Northern Hemisphere. This annual turning point results from Earth's axial tilt, which positions the Northern Hemisphere to receive the least direct sunlight of the entire year. Astronomically, the date signifies the start of winter, since seasons are defined by equinoxes and solstices rather than weather patterns.

Ancient cultures built monuments to track solstice sun points, highlighting the spiritual and symbolic weight of this moment on the solar calendar. Although the winter solstice marks the darkest day of the year, it also represents the beginning of the gradual return to longer days.

Precise Astronomical Event Behind Shortest Day

The winter solstice occurs because Earth tilts at a constant 23.5-degree angle. On December 21st, the Northern Hemisphere reaches the point in Earth’s orbit where it leans farthest from the sun. This orientation sends the sun on its lowest and shortest path across the sky, creating the longest night and the least daylight for all regions north of the equator.