The winter solstice is the day with the shortest daylight and longest night of the year in the Northern Hemisphere. It falls on December 21 or 22, depending on the year; in U.S. time zones it falls on December 21 for the next several years. At the moment of the solstice, the Sun reaches its southernmost point in the sky, directly over the Tropic of Capricorn. After the solstice, days slowly start getting longer, which is why cultures around the world have long celebrated it as the return of the light.
History of Winter Solstice
The solstice happens because Earth's axis is tilted about 23.4 degrees. As Earth orbits the Sun, the Northern Hemisphere is tilted farthest away from the Sun in December, giving it shorter days and lower sun angles. In the Southern Hemisphere, the same moment is the summer solstice, the longest day of the year.
Ancient peoples tracked the solstice carefully. Newgrange, a passage tomb in Ireland built around 3200 BC, is aligned so that sunlight enters its inner chamber at sunrise around the winter solstice. Stonehenge in England is aligned with the midwinter sunset. Many cultures held festivals at this time, including the Roman Saturnalia, the Germanic Yule, the Chinese Dongzhi Festival and the Persian Yalda Night, when families stay up late on the longest night eating pomegranates and reading poetry.
The exact time of the solstice changes each year because Earth's orbit doesn't line up perfectly with our calendar. Astronomers calculate it to the minute, and observatories and websites publish it each year.
Why Winter Solstice Matters
The winter solstice marks a turning point in the year: from this day, daylight begins to increase, bringing hope during the coldest season.
It connects modern people with ancient cultures that carefully observed the sky and built monuments around it.
Understanding the solstice also teaches important science about Earth's tilt, orbit and seasons, and explains why the seasons are reversed in the Southern Hemisphere.
How to Celebrate Winter Solstice
- Watch the sunrise or sunset: notice how low the Sun is in the sky.
- Light candles: celebrate the return of the light.
- Learn the science: model Earth's tilt with a flashlight and ball.
- Try a world tradition: eat pomegranates for Yalda or dumplings for Dongzhi.
- Stargaze: enjoy the longest night of the year.
Celebrating at Work, School and Home
At work, share the exact solstice time and celebrate the return of longer days with a 'light' theme, such as a candle-lit (or LED) lunch. In classrooms, students can measure shadows at noon over several weeks, model the seasons with a lamp and globe, or research solstice festivals around the world. At home, families can take a sunset walk, make paper lanterns, or stay up for a cozy longest-night celebration with games and hot cocoa. Check local sunrise and sunset times to see how short the day is.
Fun Facts About Winter Solstice
- Earth's axis is tilted about 23.4 degrees.
- Newgrange in Ireland is aligned with the winter solstice sunrise.
- In the Southern Hemisphere, the December solstice is the longest day.
Winter Solstice FAQs
When is the winter solstice?
The winter solstice falls on December 21 or 22 in the Northern Hemisphere, depending on the year and time zone.
Why is the winter solstice the shortest day?
On the solstice, the Northern Hemisphere is tilted farthest from the Sun, so daylight is shortest.
Do days get longer after the winter solstice?
Yes, daylight gradually increases each day after the winter solstice until the summer solstice in June.
Is the winter solstice the first day of winter?
It is the first day of astronomical winter; meteorologists count winter from December 1.
What is the winter solstice in the Southern Hemisphere?
In the Southern Hemisphere, the December solstice is the summer solstice, the longest day of the year.
What traditions celebrate the winter solstice?
Yule, Dongzhi, Yalda Night and ancient festivals at sites like Newgrange and Stonehenge.