By Susan Smith Kline
The first day of winter in the Northern Hemisphere is marked by the winter solstice, which occurs on Wednesday, December 21, 2022, at 3:48PM CST. This means the Earth’s Northern Hemisphere is tilted as far away from the sun as possible, and that half of the planet will see the shortest hours of sunlight and the longest dark hours of the year.
The word solstice comes from the Latin sol “sun” and sistere “to stand still.” Loosely translated, it means “sun stand still.” For a few days before and after the solstice, the Sun’s path across the sky appears to freeze. The change in its noontime elevation is so slight that the Sun’s path seems to stay the same, or stand still.
The winter solstice marks the official beginning of astronomical winter (as opposed to meteorological winter, which starts about three weeks before the solstice). The winter solstice occurs once a year in each hemisphere: once in the Northern Hemisphere (in December) and once in the Southern Hemisphere (in June). It marks the start of each hemisphere’s winter season. When one hemisphere is experiencing its winter solstice, the other is simultaneously experiencing its summer solstice.
It will be the day with the fewest hours of sunlight in the entire year, making it the “shortest day” of the year. Thankfully, after we reach the winter solstice, the days begin to once again grow longer and longer until we reach the summer solstice – the first day of summer and the longest day of the year.
This is all thanks to Earth’s tilted axis, which makes it so that one-half of Earth is pointed away from the Sun and the other half is pointed towards it at the time of the solstice. On the day of the winter solstice, we are tilted as far away from the Sun as possible, which means that the Sun’s path across the sky is as low in the sky as it can be. Think about the daily path of the Sun. it rises in the east and sets in the west, arcing across the sky overhead. During the summer, the Sun arcs high in the sky, but during the winter, it arcs lower, closer to the horizon.
We often think of the winter solstice as an event that spans an entire calendar day, but the solstice actually lasts only a moment. Specifically, it’s the exact moment when a hemisphere is tilted as far away from the Sun as it can be.
There are effects of the solstice we can observe. On the day of the solstice, stand outside at noon and look at your shadow. It is the longest shadow that you will cast all year. Do this again on the day of the summer solstice and you will see almost no shadow.
Although the winter solstice means the start of winter, it also means the return of more sunlight. It only gets brighter from here and this is the thought that keeps me going!