December Solstice (Shortest Day)
December 21 @ 4:20 am
December Solstice in Boston, Massachusetts
There are two solstices every year: one in December and one in June. The December solstice marks the shortest day north of the equator and the longest day in the south.
During the course of a year, the subsolar point—the spot on the Earth’s surface directly beneath the Sun—slowly moves along a north-south axis. Having reached its northernmost point at the June solstice, it starts moving southward until it crosses the equator on the day of the September equinox. At the December solstice, which marks the southernmost point of its journey, it stops again to start its journey back toward the north.
The term “solstice” comes from the Latin words sol and sistere, meaning “Sun” and “to stand still.”