The December Solstice will occur at 10:03 a.m. EST on 21 December 2025, according to the Earth's Seasons - Equinoxes, Solstices, Perihelion, and Aphelion page, Astronomical Applications Department, U.S. Naval Observatory.
The Motions of the Sun Simulator can be used to explore the apparent motion of the Sun across the sky on the December Solstice. The following screenshot shows the simulator configured for 21 December at 12 noon. Be sure to set the "animation mode" for "continuous" and "loop day," as shown in the red rectangle on the graphic.
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| "Motions of the Sun Simulator" set for DEC 21. |
Notice the Sun rises along the southeastern horizon and sets along the southwestern horizon. At Washington, D.C. (38.89° North latitude and 77.03° degrees West longitude) the Sun reaches a maximum altitude of ~28° above the horizon, the lowest maximum altitude all year.
Also notice the odd-looking figure eight that is shown in red on the preceding screenshot. It's called an analemma. The crest of the figure eight shows the Sun's maximum altitude on the June Solstice.
Related Resources
- Motions of the Sun Simulator
- Earth's Seasons - Equinoxes, Solstices, Perihelion, and Aphelion - Astronomical Applications Department, U.S. Naval Observatory
- Altitude and Azimuth of the Sun or Moon During One Day - Astronomical Applications Department, U.S. Naval Observatory
Copyright © 2025 by Walter Sanford. All rights reserved.
