Solstices occur twice a year, in June and December, when the sun reaches its northernmost or southernmost point relative to the Earth’s axis. Traditionally, they were important religious festivals, and druid ceremonies still take place at sites like Stonehenge.
The terms Summer and Winter Solstice can be misleading as the seasons depend on the hemisphere. Sailors prefer the terms Northern and Southern Solstice, as these indicate the position of the Sun.
The Southern Solstice occurs in December.