Today marks the winter solstice, the shortest day of the year in the Northern Hemisphere (and the longest day of the year in the Southern Hemisphere). The second solstice occurs in June, which is when the longest day of the year in the Northern Hemisphere occurs.
This solstice happened for everyone on Earth on December 21 at 11:48 p.m. ET (though the 22nd is the day it is “officially” counted as).
While this day is also known as the darkest day of the year, it is also seen as a moment to celebrate the return of longer days to come. Many cultures and religions celebrate holidays (Christmas, Hanukkah, Kwanzaa, pagan festivals, etc.) around this time of the year to mark the return of the sun and longer days.
So bundle up, settle down in front of a roaring fire and stay warm through our longest night. Warmer weather and longer days are on their way.
Thanks to the CNN article that provided easily summable information.