June 21 marks the longest day and the shortest night in the northern hemisphere.
Hanukkah has already begun, but Christmas, Kwanzaa and the Winter Solstice are all still on the way.
As the U.S. and the rest of the Northern Hemisphere mark the summer solstice, Australia, Antarctica and others are in the middle of winter.
From hula-hoopers to young lovers, these are the best photos from the U.K's solstice celebrations.
The sun could shine for as long as 16 hours in some parts of the U.S.
This year's summer solstice coincides with the strawberry moon for the first time since 1967.