Winter begins Sunday Afternoon


The official beginning of winter across the northern hemisphere will occur Sunday afternoon, December 21st at 4:03 P.M. Mountain Standard Time.  This is known as the winter solstice and it marks the moment when the Sun’s overhead position reaches its maximum southerly latitude, directly over the imaginary line known as the Tropic of Capricorn. It also signals the shortest “day” of the year for the northern hemisphere, day being defined as the amount of time between sunrise and sunset. At our latitude that is about 9 hours and 10 minutes.
The winter season over the northern hemisphere will last for 89 days and 42 minutes, which is the shortest of the 4 seasons over the northern hemisphere. The seasons are not of equal length because the Earth does not orbit the Sun at a constant velocity, but speeds up and slows down as the year progresses.
Starting Monday the 22nd the lengths of the daytimes will begin to grow as the Sun begins its annual trek northward. Only a few seconds are gained each day initially, but that will increase as spring approaches. Spring will arrive over the northern hemisphere next March 20th at 4:45 PM MDT.

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