Winter solstice 12-21

(GOOOGLE DOODLE)

As the winter arrives, the sun's maximum elevation during the day, the elevation at noon, gets lower. This maximum elevation attains its lowest value at the winter solstice and after that it starts to increase.

When it is Winter Solstice in the Northern Hemisphere, it is the summer solstice in theSouthern Hemisphere.

For the Northern Hemisphere, at the moment of winter solstice, the sun is at its greatest height as observed from the South Pole. Similarly, for the Southern Hemisphere, at the moment of the winter solstice, the sun is at its greatest height as observed from the North Pole.  In the Northern Hemisphere the winter solstice is also the Southern solstice and occurs in December, In the Southern Hemisphere this is theNorthern solstice which occurs in June.

Depending on one's position on the globe, the December solstice usually occurs on the 21st and the 22nd and the June solstice usually occurs on June the 20th or 21st. However, it is sometimes possible for a solstice to coincide with three different dates. Thus the December 2016 solstice coincides with 20th of the month in American Samoa, with the 21st in London and with the 22nd at Kirtimati.

Source Wikipedia