Winter solstice, or Southern solstice in the Northern hemisphere, is the time of year in which the sun is at its most southern point in the sky. This event occurs every year on December 21 to December 22. The Sun will appear at its lowest point above the horizon at noon and shine directly over the Tropic of Capricorn. Winter solstice also marks the point at which winter officially begins.
The reason for the seasons can be explained by Earth’s axial tilt, and Earth’s rotation on this axis as it also rotates around the Sun. The axis is tilted at about 23.5 degrees, causing the Northern hemisphere and the Southern hemisphere to experience different seasons at different times. Due to the Earth’s tilt, while the Northern hemisphere is receiving less sunlight, causing winter, our friends down under in the Southern hemisphere are soaking up more sunlight and experiencing summer.
Though not readily apparent except to those in high elevations, the winter solstice marks the shortest day and longest night of the year. For several days around the solstice, the sun’s maximum elevation in the sky is at its lowest. The word solstice was derived from the Latin word “solstitium,” from sol meaning “sun” and -stitium meaning “a stoppage.” After the solstice, the days once again start to become longer and the nights shorter.
Though winter is usually regarded as a time of dormancy, the return of light became a reason for celebration in many cultures. These celebrations and festivals vary from being astronomical to symbolic to ritualistic, and many have evolved depending on how cultures developed. For a full list of winter festivals, go here.
Happy Winter Solstice!