Graphic showing how Earth's Northern Hemisphere is tilted away from the Sun's during the Winter Solstice in that half of the world while the Southern Hemisphere is tilted toward the Sun at the same time, marking Summer Solstice there.


Monday, December 21



Target Audience:

General Audience


The December solstice, which occurs on December 21 this year, marks the winter solstice in the Northern Hemisphere and the summer solstice in the Southern Hemisphere. On the December solstice, the Sun reaches its southernmost position in the sky, no matter where on Earth you happen to be.

The Sun's changing height in the sky throughout the year is caused by Earth's tilt as it orbits our local star.

Learn more in this month's episode of NASA's "What's Up" video series:

Here's what you can see in the sky in December 2020. | Watch on YouTube

For more details and skywatching tips, visit NASA's Solar System Exploration website.

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Events are based on visibility in the Northern Hemisphere. Dates and clock times are for the Pacific time zone unless otherwise noted.