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.
For us in the Northern Hemisphere, the December solstice will mark the longest nights and shortest days of the year. For the Southern Hemisphere, it will mark the shortest nights and longest days. After this solstice, the sun will move north again.
In 2024, the December solstice falls at 9:21 UTC (3:21 AM CT) on December 21.
Information from EarthSky
In the Northern Hemisphere, you’ll notice late dawns and early sunsets, the low arc of the sun across the sky each day, and how low the sun appears in the sky at local noon. Look at your noontime shadow, too. Around the time of the December solstice, it’s your longest noontime shadow of the year. -EarthSky
Another way to think of this is that on the day of the solstice, the Sun’s path reaches its most southerly point in the sky. For those of us in the Northern Hemisphere, this means that the Sun’s path is as low in the sky as it can get—even at “high noon.” -Almanac
Information from Reader's Digest, Farmer's Almanac, and Des Moines Register
Since ancient times, people all over the world have recognized this important astronomical occurrence and celebrated the subsequent “return” of the Sun in a variety of different ways. Old solstice traditions have influenced the holidays we celebrate now, such as Christmas and Hanukkah. Here are some solstice traditions, both new and old, to help light your way to longer days.
Information from Britannica.
The apparent position of the Sun in the sky changes throughout the year. During the summer months, it rises higher in the sky and is above the horizon for longer. In the winter, the Sun's position is lower and its time in the sky is shorter.
This variation happens because the Earth orbits at an angle: it is tilted 23.4 degrees on its axis.
During summer in the northern hemisphere, the North Pole is tilted towards the Sun, and therefore, this part of the Earth receives more direct sunlight and longer daylight hours. During winter in the northern hemisphere, the North Pole is tilted away from the Sun, resulting in fewer daylight hours. -Royal Museums Greenwich