Winter may just be getting started, but if you’re ready for more sunlight, you won’t have much longer to wait. Dec. 21 is the winter solstice: the shortest day and longest night of the year here in Earth’s northern hemisphere.
Starting Friday, the sun will be up for a few seconds longer each day, signaling the start of our slow but steady march toward spring. But let’s not get ahead of ourselves. Winter is just getting into high gear. Learn more about the solstice and why it’s not the coldest day of the year in our scientific guide below.
1. What happens on the winter solstice?
The December solstice marks the exact moment when the sun’s most direct rays reach their southernmost point south of the equator, along the Tropic of Capricorn, at 23.5 degrees south latitude. The time and date of the solstice change slightly each year, but this year’s solstice occurs at 11:28 a.m. Eastern Time on Dec. 21.
The reason we have a solstice — and seasons — is because the Earth is tilted on its axis of rotation by about 23.5 degrees. This tilt causes each hemisphere to receive different amounts of sunlight throughout the year as our planet orbits the sun. In the Northern Hemisphere, we see the sun take its lowest and shortest path across the southern sky, and at local noon, your shadow will be the longest of the year.
The word “solstice” comes from the Latin words sol sistere, which means “sun standing still.” On the December solstice, the sun’s daily southward movement in the sky appears to pause, and we see the sun rise and set at its southernmost points on the horizon before reversing direction. It’s a yearly astronomical turning point that humans have celebrated for millennia (just think Stonehenge or the ancient Maya).
2. How many hours of daylight are there on the winter solstice?
The amount of daylight you’ll see on the solstice depends on your latitude, or distance from the equator. The map below, created by Alaska-based climatologist Brian Brettschneider, shows how widely daylight hours vary across North America on the shortest day of the year.
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Originally Posted by Zippyjuan
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