There are two solstices—one on June 21 and the other on December 21. On June 21, the sun is directly above the Tropic of Cancer at noon and heralds the beginning of summer in the Northern Hemisphere and the beginning of winter in the Southern Hemisphere. On December 21, the sun is directly above the Tropic of Capricorn at noon and heralds the beginning of winter in the Northern Hemisphere and the beginning of summer in the Southern Hemisphere.