The December solstice will come on December 22, 2019, at 04:19 UTC. That’s 10:19 p.m. (22:19) CST on December 21 for those in the central time zone in North America. It’s when the sun reaches its southernmost point for the year. This solstice marks the beginning of the winter season in the Northern Hemisphere, and the start of the summer season in the Southern Hemisphere. And, no matter where you are on Earth, it marks the beginning of your shortest season.
By season, we mean the time between a solstice and an equinox, or vice versa. The upcoming season – between the December solstice and March equinox – is a touch shy of 89 days.