For many people in the US, winter has come a little early, as a few waves of snow and blisteringly cold temperatures have colored the landscape white. It isn’t officially winter yet, and it won’t be until Dec. 21 when the winter solstice takes place. So get ready because Earth’s shortest day is on its way.

What is the winter solstice?

The winter solstice has a few different meanings, so here are all of them. The most common definition, and the one you’re most likely familiar with, is that it denotes the shortest day and longest night of the year on Earth. These times vary depending on your location on the globe, but the further north you live, the less sunlight you’ll get. In the tropics, they’ll get about 12 hours of sunlight. In Sweden, it’ll be closer to six hours. In Svalbard, there isn’t any.

The reason this occurs is due to the second definition of the winter solstice: During this time, the North Pole is tilted as far away from the sun as it can get. According to The Farmer’s Almanac, the moment at which the Earth’s axis is physically tilted as much as it can be is at 10:03 a.m. ET on Dec. 21. After that moment, the process will begin to reverse until the South Pole takes its turn during the summer solstice. At that point, the North Pole will be at its closest tilt to the sun, giving us the longest day and shortest night of the year for the Northern Hemisphere.

How much sunlight will we get?

It’ll vary by location. The southern US will have the most sunlight, with Florida getting a little over 10 hours during the winter solstice. The Midwest and Great Lakes portion of the country will get roughly nine hours. The Pacific Northwest can expect a little less than nine hours. Southern Alaska will get about six hours, and the northern areas of Alaska will see around three hours. 

If you want to see how your area will fare, Time and Date has a sunrise and sunset tool you can use. Input your zip code into the search bar, and you’ll be able to see your sunrise and sunset times. 

The city of Utqiaġvik, Alaska, will have it worse than most in the US: It won’t get any sun at all. The sun won’t rise there again until Jan. 22. We hope the people living there packed their vitamin D supplements. 

The difference between a solstice and an equinox

The autumn equinox was just a few months ago, so you may be curious about the differences. A solstice occurs when the Earth’s poles are tilted as far away from the sun as they’ll be over the course of one year, which is also one orbit around the sun. The equinoxes take place at the halfway points between each solstice. The autumn equinox takes place in September between the summer and winter solstices, while the spring equinox takes place in March between the winter and summer. 

During an equinox, the poles are minimally tilted, and the days are as even as they can be. This also has a couple of other interesting side effects: The sun is pointed directly at the equator during an equinox, and the sun will rise and set directly east and west, respectively. 

Humans use the solstices and equinoxes to mark the change of the seasons. There are two equinoxes and two solstices, which mark the start and end dates for Earth’s four seasons. 

Celebrating the winter solstice

While the solstice is close to the holidays, celebrations for the winter solstice have been around for significantly longer, and some winter solstice traditions have become Christmas traditions as well. One of the most historically famous winter solstice celebrations is Yule, a winter festival originating thousands of years ago among the Ancient Norse. It became commonly celebrated in Europe and involved bonfires and massive feasts. Yule celebrations also included decorating with evergreen tree decorations, like holly and ivy.

If these sound familiar, it’s because Christmas co-opted many of those traditions centuries ago, and the two traditions have kind of merged into a single seasonal holiday. The terms Yule and Christmas are often used interchangeably these days in many cultures.

So if you want to celebrate the winter solstice, just do all of the stuff you would normally do for the holidays. Burn a Yule log, decorate a tree, eat a big feast with your family and hang up mistletoe and wreaths — those are all hat tips to traditional winter solstice celebrations.