The winter solstice, also known as midwinter takes place today (December 21, 2017).
It is an astronomical phenomenon marking the day with the shortest period of daylight, coupled with the longest night of the year.
Quite simply it is the shortest day, longest night.
This period is also called: Yule or Midwinter.
Astronomically its significance marks the beginning of shortening nights and lengthening days and closely relates to Winter festivals and the solstice.
This occurs around December 21 in the Northern Hemisphere and approximately June 21 in the Southern Hemisphere.
Interestingly, winter in meteorological terms started on December 1, (2017) and ends on February 28, (2018).
When does winter start this year?
How you define the first day of winter depends on if you mean either the astronomical or meteorological winter.
The meteorological winter began on December 1, 2017, and will end on February 28, 2018.
Meteorological seasons consists of four periods (three months in each) an coincide with the Gregorian calendar we use.
Therefore, by this calendar, winter always starts on December 1.
The Astronomical winter starts December 21, (2017) – March 20, (2018).
It determines the seasons as the Earth’s tilt in relation to its orbit around the sun effect both equinoxes and solstices.