December solstice 2025: All you need to know

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The December solstice is the time of year when the sun reaches its southernmost point in the sky. This point is directly above the Tropic of Capricorn—a parallel line 23.5° south of Earth’s equator.

Satellite view of Earth during equinoxes and solstices. On the December solstice, the terminator—the line between light and dark—appears slanted because the sun sits directly above the Tropic of Capricorn, shining more light on the Southern Hemisphere. (Image credit: NASA’s Earth Observatory)

December solstice 2025

When it occurs: The December solstice will fall on December 21, 2025, at 15:03 UTC (10:03 a.m. EST).

Effect on day and night: As the sun shines directly above the Tropic of Capricorn on December 21, 2025, the Northern Hemisphere will receive the most indirect sunlight, while the Southern Hemisphere will receive the most direct sunlight.

As a result, the December solstice on December 21, 2025, will bring the shortest day and longest night of the year in the Northern Hemisphere. However, in the Southern Hemisphere, it will bring the longest day and shortest night of the year.

After the December solstice, the sun will move northward in the sky until the June solstice on June 21, 2026. As a result, days will get longer and nights shorter in the Northern Hemisphere. However, in the Southern Hemisphere, days will get shorter and nights longer.

Effect on season: The December solstice on December 21, 2025, will mark the beginning of astronomical winter (the winter solstice) in the Northern Hemisphere and astronomical summer (the summer solstice) in the Southern Hemisphere.

Effect on sunrise and sunset: On the December solstice, December 21, 2025, the sun will rise farthest south of east and set farthest south of west, no matter where you are on the globe.

After the December solstice, the sun will rise and set a bit farther north on the horizon each day until the June solstice on June 21, 2026.

Zaid M. Al-Abbadi captured the sunrise direction each month in 2019 from near the city of Amman, Jordan. The sun rises due east on the equinoxes. However, it rises farthest north of east on the June solstice and farthest south of east on the December solstice. (Image credit: Zaid M. Al-Abbadi/APOD)

Effect on the sun’s path: On the December solstice, December 21, 2025, the sun will follow its shortest path across the sky and reach its lowest elevation at noon in the Northern Hemisphere. However, in the Southern Hemisphere, it will follow the longest path and reach its highest elevation at noon.

Hunter Wells created this analemma by photographing the sun on the indicated dates only, from March 10, 2024, to March 1, 2025, at 18:38 UTC, from the exact same location south of Stephenville, Texas. The sun’s position was at the top of the curve during the June solstice of 2024 and at the bottom during the December solstice of 2024. (Image credit: Hunter Wells/APOD)

Why does the December solstice occur?

The sun shines directly above the Tropic of Capricorn during the December solstice. (Image credit: NASA’s Goddard Space Flight Center)

Earth’s rotational axis is tilted about 23.5° from the perpendicular to its orbital plane around the sun.

However, the orientation of Earth’s axial tilt relative to the sun changes throughout the year as Earth orbits the sun.

The December solstice occurs when Earth’s tilt away from the sun is at a maximum and the sun is directly above the Tropic of Capricorn, the southernmost latitude it reaches annually.

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