The December or Winter Solstice occurs when the sun reaches its most southerly declination of -23.5 degrees. In other words, it’s when the North Pole is tilted 23.5 degrees away from the sun. Depending on the Gregorian calendar, the winter solstice occurs annually on a day between December 20th and December 23rd. On this date, all places above a latitude of 66.5 degrees north (Arctic Polar Circle) are now in darkness, while locations below a latitude of 66.5 degrees south (Antarctic Polar Circle) receive 24 hours of daylight.You can use the Sunrise and Sunset calculator to find the number of daylight hours during the winter solstice in cities worldwide.
The sun is directly overhead on the Tropic of Capricorn in the Southern Hemisphere during the December solstice. It also marks the longest day of the year in terms of daylight hours for those living South of the equator. Those living or traveling South from the Antarctic Circle towards the South Pole will see the midnight sun during this time of the year.
On the contrary, for an observer in the Northern Hemisphere, the December solstice marks the day of the year with the least hours of daylight. Those living or traveling North of the Arctic Circle towards the North Pole will not be able to see the sun during this time of the year.
December 20th and December 23rd solstices occur less frequently than December 21st or December 22nd solstices in the Gregorian calendar. The last December 23rd solstice occurred in 1903, and will not occur again until the year 2303. A December 20th solstice has occurred very rarely, with the next one occurring in the year 2080.