Saturday is the winter solstice and 2024’s shortest day. Here’s what to know about the official start of winter.

The 2024 winter solstice, the shortest day of the year, happens on Saturday, Dec. 21, in the Northern Hemisphere. The celestial event signifies the first day of winter, astronomically. 

What is the winter solstice?

The winter solstice is the day each year that has the shortest period of daylight between sunrise and sunset, and therefore the longest night. It happens when the sun is directly above the Tropic of Capricorn, a line of latitude that circles the globe south of the equator, the National Weather Service explains. 

The farther north you are, the shorter the day will be, and in the Arctic Circle, the sun won’t rise at all. 

How is the day of the winter solstice determined?

The winter solstice occurs because of the Earth’s tilt as it rotates around the sun. 

When the Northern Hemisphere tilts away from the sun, the nights last longer. The longest night happens on the solstice because the hemisphere is in its furthest position from the sun. That occurs each year on Dec. 21 or 22. 

This year, it falls on Dec. 21 at 4:21 a.m ET, to be precise.

On the summer solstice, when the northern tilt is closest to the sun, we have the longest day, usually June 20 or 21.

The solstices are not always exactly on the 21st every year because the earth’s rotation around the sun is 365.25 days, instead of 365 even. 

Will days start getting longer after the winter solstice?

Yes. Each day after the solstice, we get one minute more of sunlight. It doesn’t sound like much, but after just two months, or around 60 days, we’ll be seeing about an hour more of sunlight. 

When will winter officially be over in 2025?

The meteorological winter ends on March 20, 2025. Then, spring will last until June 20, when the summer solstice arrives. 

How is the winter solstice celebrated around the world?

Nations and cultures around the world have celebrated the solstice since ancient times with varying rituals and traditions. The influence of those solstice traditions can still be seen in our celebrations of holidays like Christmas and Hanukkah, Britannica notes.

The ancient Roman Saturnalia festival celebrated the end of the planting season and has close ties with modern-day Christmas. It honored Saturn, the god of harvest and farming. The multiple-day affair had lots of food, games and celebrations. Presents were given to children and the poor, and slaves were allowed to stop working. 

Gatherings are held every year at Stonehenge, a monumental circle of massive stones in England that dates back about 5,000 years. The origins of Stonehenge are shrouded in mystery, but it was built to align with the sun on solstice days. 

The Hopi, a Native American tribe in the northern Arizona area, celebrate the winter solstice with dancing, purification and sometimes gift-giving. A sacred ritual known as the Soyal Ceremony marks the annual milestone.

In Peru, people honor the return of the sun god on the winter solstice. The ancient tradition would be to hold sacrificial ceremonies, but today, people hold mock sacrifices to celebrate. Because Peru is in the Southern Hemisphere, their winter solstice happens in June, when the Northern Hemisphere is marking its summer solstice.

Scandinavia celebrates St. Lucia’s Day, a festival of lights. 

The “arrival of winter,” or Dong Zhi, is a Chinese festival where family gathers to celebrate the year so far. Traditional foods include tang yuan, sweet rice balls with a black sesame filling. It’s believed to have its origins in post-harvest celebrations. 

Researchers stationed in in Antarctica even have their own traditions, which may include an icy plunge into the polar waters. They celebrate “midwinter” with festive meals, movies and sometimes homemade gifts.