December solstice 2017 arrives on December 21 at 16 28 UTC. High summer for the Southern Hemisphere. For the Northern Hemisphere, the return of more sunlight! http://earthsky.org/astronomy-essenti... The winter solstice is when the Sun's rays are directly over the tropic of capricorn 23 1/2 degrees south of the equator. The solstice is when the Earth is tilted most away from the Sun on its axis. The winter solstice marks the longest night and shortest day in the northern hemisphere while in the southern hemisphere will have their longest day. The Sun stays below the north pole horizon during the winter solstice. This is the beginning of the winter in the northern hemisphere. Days will begin lengthening after winter solstice. That leads up to the summer solstice in June. The winter solstice is different than the equinox. The equinox is when the Sun's rays are directly over the equator. That happens twice a year when day and night are equal lengths. Happy Solstice Everyone! Clips, images credit: California Academy of Sciences, NASA Goddard Space Flight Center & NWS Music credit: YouTube Audio Library