The December solstice marks the sun’s southernmost point in the sky, for the entire globe, for this entire year. On this solstice, the sun will be overhead at noon as viewed from the Tropic of Capricorn. In 2023, the December solstice falls at 3:27 UTC on December 22 (9:27 p.m. CST on December 21). For us in the Northern Hemisphere, it is the shortest day of the year before they slowly start to lengthen again. You can read more about it at EarthSky at https://earthsky.org/astronomy-essentials/everything-you-need-to-know-december-solstice/. The December solstice marks the beginning of astronomical winter in the Northern Hemisphere, although climatological winter began on December 1.