June Solstice (Longest Day)
June 20, 2025
June Solstice in Boston, Massachusetts
There are two solstices every year: one in June and one in December. The June solstice marks the longest day north of the equator and the shortest day in the south.
During 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 southernmost point at the December solstice, it stops and starts moving northward until it crosses the equator on the day of the March equinox. At the June solstice, which marks the northernmost point of its journey, it stops again to start its journey back toward the south.
The term “solstice” comes from the Latin words sol and sistere, meaning “Sun” and “to stand still.”