The winter solstice happens on Tuesday, December 21, 2021! This is the astronomical first day of winter in the Northern Hemisphere and the shortest day of the year. What happens at the winter solstice? Why is the solstice important? Enjoy solstice facts and folklore from The Old Farmer’s Almanac.
When Is the First Day of Winter?
The first day of winter in the Northern Hemisphere is marked by the winter solstice, which occurs on Tuesday, December 21, 2021, at 10:59 A.M. EST.
For the northern half of Earth (the Northern Hemisphere), the winter solstice occurs annually on December 21 or 22. (For the Southern Hemisphere, the winter solstice occurs on June 20 or 21.) The winter solstice is the day with the fewest hours of sunlight in the whole 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.
Think of it this way: Although the winter solstice means the start of winter, it also means the return of more sunlight. It only gets brighter from here!
What Is the Winter Solstice?
The winter solstice marks the official beginning of astronomical winter (as opposed to meteorological winter, which starts about three weeks prior to 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 their winter solstice, the other is simultaneously experiencing their summer solstice!
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.
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. This is shown in the diagram below.
The winter solstice holds significance across a variety of cultures, as it signals the changing of the seasons. Some ancient peoples even marked the solstice using huge stone structures, like Newgrange in Ireland. In some cultures, the solstice traditionally marked the midway point of the season rather than the start of it, which explains why holidays such as Midsummer Day are celebrated around the first day of summer.
What Happens on the Winter 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.
How can we observe the effects of solstice ourselves? On the day of the solstice, stand outside at noon and look at your shadow. It’s the longest shadow that you’ll cast all year! Do this again on the day of the summer solstice and you’ll see almost no shadow.
The Sun’s Changing Path
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.” In the Southern Hemisphere, it’s the opposite: The Sun’s path will be high in the sky on the winter solstice—directly overhead at noon at the latitude called the Tropic of Capricorn, which is an imaginary line that circles the Earth, running through parts of South America, southern Africa, and Australia.
The word solstice comes from Latin sol “sun” and sistere “to stand still.” So, loosely translated, it means “sun stand still.” Why? 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 day after the winter solstice, the Sun’s path begins to advance northward again, eventually reaching its most northerly point on the day of the summer solstice.
You may also be familiar with the term “equinox.” In the spring (March) and the fall (September), the Sun’s path bring it directly above Earth’s equator. Equinox means “equal,” as day and night on the equinoxes are of roughly equal length.
Common Questions About the Winter Solstice
The Winter Solstice is the shortest day of the year. Is it also the coldest?
The day of the winter solstice is the shortest day of the year, which means that it’s the day in which we experience the least amount of daylight. Logically, it would make sense to assume that this is also the coldest day of the year, since we are exposed to less warmth-giving sunlight on this day than at any other time. But this is not true.
There are a lot of factors that affect the temperature of a location on any given day, including altitude, snow cover, and large-scale weather patterns. Snow cover, for example, partially blocks solar radiation from being absorbed by the Earth, which results in less heat being released and an overall drop in temperature. Because of these factors, it’s not possible to point to the same date year after year and call it the coldest day.
In the United States, the coldest days of the year tend to occur between mid-December and late January, so while it’s certainly possible that the coldest day of the year could also be the day of the winter solstice, that’s not usually the case!
Is the Winter Solstice really the start of winter?
There is not a black-and-white answer to this question—it depends on which definition of “winter” you follow:
Astronomical winter begins at the winter solstice and ends at the spring equinox. Astronomical seasons are based on the position of Earth in relation to the Sun.
Meteorological winter (in the Northern Hemisphere) starts on December 1 and ends on February 28 (or 29). Meteorological seasons are based on the annual temperature cycle and climatological patterns observed on Earth.
However, that doesn’t mean that the meteorological definition is incorrect. It is important for meteorologists to be able to compare climatological statistics for a particular season from one year to the next—for agriculture, commerce, and a variety of other purposes. Thus, meteorologists break the seasons down into groupings of three months. Meteorological winter starts on December 1 and includes December, January, and February.
Did you know? For the ancient Celts, the calendar was based around the solstices and equinoxes, marking the Quarter Days, with the mid-points called Cross-Quarter Days. Learn more about the Celtic calendar.
Winter Solstice: Our Ancestors’ Customs and Traditions.
The solstice has been celebrated since ancient times by cultures around our planet. From the Roman feast of Saturnalia to the pre-Christian festival of Norse jól or Juul observed in Scandinavia, there are many ways our ancestors honored the first day of winter. Learn more about “Winter Solstice: Our Ancestors’ Customs and Traditions.”
Was Stonehenge Built to Celebrate the Winter Solstice?
One famous ancient marker is Stonehenge in England. Due to the alignment of the stones, experts acknowledge that the design appears to correspond with the solstices. One theory is that the area was used as a temple to worship the Sun and/or as a type of astronomical observatory. Read more about Ancient Sites Aligned with the Solstice and Equinox.
Winter Folklore and Verse
Here at the Almanac, we love our weather folklore.
Deep snow in winter; tall grain in summer. —Estonian proverb
Visits should be short, like a winter’s day.
A fair day in winter is the mother of a storm. —English proverb
Summer comes with a bound; winter comes yawning.
Onion skins very thin, mild winter coming in.
Taken from https://www.almanac.com/content/first-day-winter-winter-solstice
Till next time this is Becky Litterer, Becky’s Greenhouse, Dougherty Iowa firstname.lastname@example.org 641-794-3337 cell 641-903-9365