Amid the whirl of the holiday season, many are vaguely aware of the approach of the winter solstice, but how much do you really know about it? Whether you're a fan of winter or just wish it would go away, here are 25 things to note—or even celebrate—about the shortest day of the year.

1. The winter solstice happens on December 21 in 2021.

Sun setting behind a tree in the winter
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The date of the winter solstice varies from year to year, and can fall anywhere between December 20 and December 23, with the 21st or 22nd being the most common dates. The reason for this is because the tropical year—the time it takes for the sun to return to the same spot relative to Earth—is different from the calendar year. The next solstice occurring on December 20 will not happen until 2080, and the next December 23 solstice will not occur until 2303.

2. The winter solstice happens at a brief, specific moment.

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Not only does the solstice occur on a specific day, but it also occurs at a specific time of day, corresponding to the instant the North Pole is aimed farthest away from the sun on the 23.5° tilt of the Earth's axis. This is also the time when the sun shines directly over the Tropic of Capricorn. In 2021, this moment occurs at 3:59 p.m. UTC (Coordinated Universal Time) on December 21. For those on Eastern Standard Time, the solstice will occur at 10:59 a.m on December 21. And regardless of where you live, the solstice happens at the same moment for everyone on the planet.

3. The winter solstice marks the longest night and shortest day of the year for the Northern hemisphere.

sun setting over Central Park
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As most are keenly aware, daylight hours grow shorter and shorter as the winter solstice approaches, and begin to slowly lengthen afterward. It's no wonder that the day of the solstice is referred to in some cultures as the "shortest day of the year" or "extreme of winter." Washington, D.C. will experience 9 hours and 26 minutes of sunlight. Helsinki, Finland, will get 5 hours and 49 minutes of light. Utqiagvik (formerly Barrow), Alaska, will not have a sunrise at all (and hasn't since mid-November; its next sunrise will be on January 22), while the North Pole has had no sunrise since October. The South Pole, though, will be basking in the glow of the midnight sun, which won't set until March.

4. Ancient cultures viewed the winter solstice as a time of death and rebirth.

snow on tree branches
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The seeming death of the light and very real threat of starvation over the winter months would have weighed heavily on early societies, who held varied solstice celebrations and rites meant to herald the return of the sun and hope for new life. Cattle and other animals were slaughtered around midwinter, followed by feasting on what was the last fresh meat for several months. The modern Druidic celebration Alban Arthan reveres the death of the Old Sun and birth of the New Sun.

5. The shortest day of the year marks the discovery of new and strange worlds.

Pilgrims landing at Plymouth Rock
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The Pilgrims arrived at Plymouth on December 21, 1620, to establish a society in which they could worship freely. On the same day in 1898, Pierre and Marie Curie discovered radium, ushering in an atomic age. And on December 21, 1968, the Apollo 8 spacecraft launched, becoming the first crewed moon mission.

6. The word solstice translates to "sun stand still."

colorful sunset
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Solstice derives from the Latin term solstitium, containing sol, which means "sun," and the past participle stem of sistere, meaning "to make stand." This comes from the fact that the sun’s position in the sky relative to the horizon at noon, which increases and decreases throughout the year, appears to pause in the days surrounding the solstice. In modern times, we view the phenomenon of the solstice from the position of space, and of the Earth relative to the sun. Earlier peoples, however, were thinking about the sun's trajectory, how long it stayed in the sky and what sort of light it cast.

7. Stonehenge is aligned to the sunset on the winter solstice.

Stonehenge sunset
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The primary axis of Stonehenge is oriented to the setting sun. Some have theorized that the position of the sun was of religious significance to the people who built Stonehenge, while other theories hold that the monument is constructed along natural features that happen to align with it. The purpose of Stonehenge is still subject to debate, but its importance on the winter solstice continues into the modern era, as thousands of hippies, pagans, and other types of solstice enthusiasts gather there every year to celebrate the occasion.

8. Ancient Romans celebrated reversals at the midwinter festival of Saturnalia.

Saturnalia parade
A Saturnalia celebration in England in 2012.
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The holiday, which began as a festival to honor the agricultural god Saturn, was held to commemorate the dedication of his temple in 497 BCE. It quickly became a time of widespread revelry and debauchery in which societal roles were overturned, with masters serving the people they enslaved and servants being allowed to insult their masters. Mask-wearing and play-acting were also part of Saturnalia's reversals, with each household electing a King of Misrule. Saturnalia was gradually replaced by Christmas throughout the Roman Empire, but many of its customs survive as Christmas traditions.

9. Some traditions hold that dark spirits will walk the Earth on the winter solstice.

Snowy woods
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Zoroastrian lore holds that evil spirits wander the Earth and the forces of the destructive spirit Ahriman are strongest on this long night. People are encouraged to stay up most of the night in the company of one another, eating, talking, and sharing poetry and stories, to avoid any brushes with dark entities. Beliefs about the presence of evil on the longest night are also echoed in Celtic and Germanic folklore.

10. Some thought the world would end on the 2012 winter solstice.

snowy woods with sun through the trees
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December 21, 2012, corresponded to the date 13.0.0.0.0 in the Mesoamerican Long Count calendar used by the Maya, marking the end of a 5126-year cycle. Some people feared this juncture would bring about the end of the world or some other cataclysmic event. Others took a more New Age-y view (literally) and believed it heralded the birth of a new era of deep transformation for Earth and its inhabitants. In the end, neither of these things appeared to occur, leaving the world to turn through winter solstices indefinitely, or at least as long as the sun lasts.

11. Earth is closest to the sun around the winter solstice.

Sunset over a frozen lake
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Though it doesn’t feel like it in the Northern Hemisphere, Earth is closer to the sun in early January— approximately 3 million miles closer—than it is in early July. The shortest distance between the sun and a planet is called perihelion; in 2021, Earth was at perihelion on January 2.

Despite the proximity to the sun, the reason for cold temperatures is because the Northern Hemisphere receives less sunlight and has cooler temperatures in winter due to Earth’s 23.5-degree tilt. The Northern Hemisphere is tilted away from the sun in winter, and toward it in July.

12. Winter’s coldest days happen after the solstice.

Frosty tree in a snow-covered field
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January and February are the coldest days in the Northern Hemisphere despite receiving more sunlight than in December’s short days. What gives?

The delayed reaction is due to the way Earth takes in and releases heat. The planet absorbs heat during the summer months and releases it gradually throughout the fall and into the winter; it doesn’t fully cool down until January or February. By then, snow is falling in many areas, creating a reflective shield against solar radiation. So, in midwinter, our stores of heat have run out—and the warmth of the sun is not being absorbed as readily.

13. In China, they celebrate Dong Zhi at the winter solstice.

Chinese family making tang yuan
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Dong Zhi means “winter arrives” or “the arrival of winter” and is an important festival during which families gather and celebrate the past year. The festival is believed to have originated as a way to mark the end of the harvest season.

Dong Zhi also correlates to the concept of yin and yang because of the season’s balance of day and night. The most popular food during Dong Zhi are glutinous rice balls called tang yuan. Dumplings, wontons, and mutton are also part of the festivities.

14. The winter solstice marks the shortest day of the year, but not the earliest sunset.

Dried thistles and snow at sunset
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Though the winter solstice is the day with the least amount of sunlight, that’s not because of the sunset. In fact, the earliest sunset happens about two weeks prior—in 2021 in New York, for example, the winter solstice is December 21, but the earliest sunsets occur on December 7 and 8 (at 4:28 p.m.).

The discrepancy is due to the way we calculate time. Our clocks operate on an exact 24-hour schedule, but our days are technically a little longer or shorter. One day equals the time between when the sun is at its highest point in the sky, called solar noon, and the next.

A solar day is slightly longer than 24 hours during the summer and winter solstices and slightly shorter during the spring and fall equinoxes because of Earth’s tilt and orbit. During the winter solstice in New York on December 21, solar noon is actually 11:54 a.m. EST.

15. For meteorologists, winter starts before the solstice.

SNow-covered pine forest
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The winter solstice is marked on the astronomical calendar, which is based on Earth’s position in relation to the sun. The dates of the seasons vary in length and in their start dates.

Meteorologists need more consistent start and end dates to chart seasonal data, so they instead use meteorological seasons, which correspond to the calendar. Each season lasts three months. Meteorological winter, therefore, starts on December 1 and includes December, January, and February.

16. Every planet has a winter solstice.

Winter forest at dusk
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Because the solstice has to do with a planet’s tilt and orbit around the sun, every other planet in our solar system also experiences a winter solstice of sorts—though the seasons themselves look much different that ours.

The seasons on Neptune and Uranus last decades, while Venus has the shortest seasons. Mars orbits the sun in a much more elliptical way than Earth, so its years are 687 days long and its fluctuations more extreme.

17. The sun illuminates an ancient tomb in Ireland on the winter solstice.

Newgrange mound in Ireland
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Newgrange, a tomb mound built in Ireland about 1000 years before Stonehenge, lights up dramatically during the winter solstice. A roof-box above the entrance coordinates with the light from the winter solstice sunrise so that a beam of light travels the 19-meter passage and then illuminates the chamber for about 17 minutes. The attraction is so popular that visitors can only gain entrance to the chamber on solstice mornings via a lottery held in late September every year.

18. Some of Peru’s Nazca Lines converge with the sun on the winter solstice.

Nasca lines in Peru
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The 2000-year-old Nazca Lines in Peru are massive designs etched into the ground, depicting a variety of plants, animals, and shapes. Some of the straight lines are as long as 30 miles and the animals and plants as large as 1200 feet.

The geoglyphs are best viewed from the sky and remain a mystery to researchers. American historian Paul Kosok, working in the 1940s, believed the geoglyphs were related to astronomy and may have served as a calendar. Some of the lines appear to correspond to the winter solstice, as they touch the spot on the horizon where the sun sets.

19. The pagan festival of Yule honored the winter solstice.

Sunset over a snowy field
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Despite showing up in a variety of Christmas-related songs and traditions, Yule originated as an ancient pagan winter solstice festival. People would celebrate with a 12-day feast that marked the sun’s rebirth and burn a Yule log, which stayed lit for all 12 nights. Some pagans consider Yule the beginning of the new year, a time when the days start getting longer. Druids would burn Yule logs for 12 days to eliminate evil spirits and bring about good luck.

20. Mistletoe was part of some winter solstice celebrations.

Bundles of mistletoe
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Druid priests believed mistletoe, a parasitic evergreen plant that grows among oak branches, was the soul of the tree. The high priest would climb an oak on the sixth night of the new moon after the winter solstice and cut down pieces of the mistletoe, which people would wear for good luck and protection from evil spirits.

21. Winter solstice celebrants sometimes ate hallucinogenic mushrooms.

Fly agaric mushroom
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European and Asian peoples’ winter solstice ceremonies sometimes included liberal use of fly agaric mushrooms, notable for their bright red caps with white dots. The mushroom is poisonous and causes hallucinations, and can be found under oaks, firs, and spruce trees.

Rituals included drying and stringing the mushrooms near the hearth. One theory posits that the legend of Santa Claus sprang from a story of ancient shamans who would collect the mushrooms, dry them, and hand them out as gifts on the winter solstice, all while dressed in mushroom-mimicking red suits with white spots. One side effect of eating the mushrooms is a rosy, flushed face, adding to the wintery imagery—not to mention the trippy idea of flying reindeer (which have also been known to snack on the mushrooms).

22. The winter solstice marks one of the most important celebrations of the Hopi.

Winter snow on Arizona mountains
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In northern Arizona, the Hopi people celebrate Soyal, or Soyaluna, the winter solstice celebration. They welcome kachinas, or katsinam, ancestral spirits that guard over the Hopi, to dance with them and bring the sun back to the world. The ritual is usually performed in an underground room, called a kiva, and is meant to bring about a prosperous year.

23. Scandinavia celebrates St. Lucia’s Day on the winter solstice.

Full moon over a winter pine forest
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Scandinavia’s festival of lights—also known as St. Lucy’s Day or the Feast of Saint Lucy—honors a Christian martyr from the 3rd century CE while incorporating Norse solstice traditions. Girls wear white dresses with red sashes and wreaths of candles on their heads, and people light fires to banish the darkness.

The celebration takes place December 13, known as the day that St. Lucy was killed by the Romans for bringing food to persecuted Christians. Legend says that St. Lucy wore a ring of candles around her head to light the way. In the old Julian calendar, December 13 coincided with the winter solstice.

24. Iranians around the world celebrate Yalda on the winter solstice.

Items for celebrating Yalda
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Yalda Night, or Shab-e-Chelleh, is an ancient winter solstice festival celebrated December 21. Yalda means “birth,” which refers to the days getting longer as well as to the birth of Mitra, the goddess of light. Celebrants bid farewell to autumn and welcome to winter, after which daylight increases.

People usually gather at the home of the oldest friend or relative and eat nuts, watermelons, and pomegranates and read from the Divan-e-Hafiz, a 14th century collection of poems. Each person in the group makes a wish and keeps it a secret, then opens the book to a random page. The oldest person in the room reads the poem aloud, which is believed to represent the way the wish would come true.

25. A world heritage site in North America is aligned with the winter solstice.

Chaco Canyon pueblo ruins
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At Chaco Canyon in New Mexico, where Ancestral Puebloans built an elaborate city more than 1000 years ago [PDF], the sun strikes a particular petroglyph called the Sun Dagger at the summer and winter solstices. The rock carving may have been part of the Ancestral Puebloans’ sophisticated practice of astronomy.