What happens every year on December 21?

Every year on December 21, the winter solstice occurs in the Northern Hemisphere, marking the shortest day and longest night of the year. This astronomical event happens when the Earth's axial tilt is farthest from the sun, resulting in the sun's lowest position in the sky at noon. Many cultures celebrate this day with various traditions and festivities, acknowledging the return of longer daylight hours as the days gradually begin to lengthen.