2023 Winter Solstice Happens Friday, Dec. 22, in Northern Hemisphere

Summary: The 2023 winter solstice happens Friday, Dec. 22, in the Northern Hemisphere while the Southern Hemisphere experiences the event as a summer solstice.

Graphic of Earth's two solstices shows zenithal Sun at Northern Hemisphere's Tropic of Cancer in June and at Southern Hemisphere's Tropic of Capricorn in December; Wednesday, July 1, 2015, graphic by CMG Lee (Cmglee), using Thursday, July 1, 2004, NASA bitmap): Cmglee, NASA, Public Domain, via Wikimedia Commons

The 2023 winter solstice happens Friday, Dec. 22, in the Northern Hemisphere and simultaneously occurs in the Southern Hemisphere, where it takes place as the opposite season, astronomical summer.

The year's second of two solstices is scheduled for Friday, Dec. 22, at 3:27 Coordinated Universal Time (UTC), according to "2023 December solstice: All you need to know," posted June 1, 2023, by Deborah Byrd on her EarthSky website. Conversion to Central Standard Time (CST) places the December solstice at 9:27 p.m. on Thursday, Dec. 21 for central North America.

The United States mostly experiences the December solstice as a winter opener. Two territories of the United States, however, associate the December solstice with the commencement of astronomical summer. American Samoa and Jarvis Island comprise the only components of the United States lying in the Southern Hemisphere.

Local time for American Samoa and Jarvis Island lags 11 hours behind Coordinated Universal Time (UTC), Earth's primary time standard. The two South Pacific Ocean territories register their summer solstice at 4:27 p.m. on Thursday, Dec. 21, 2023.

The Sun's position overhead occurs at noon on the December solstice at the Tropic of Capricorn. As one of Earth's five major circles of latitude, the Tropic of Capricorn equates to the 23rd parallel south. The overhead occurrence marks the southernmost reach of the subsolar point on Earth's surface.

As the tracker of the overhead sun, the subsolar point traces a north-south passage across Earth's surface. The Tropic of Cancer, the Northern Hemisphere's equivalent of the Tropic of Capricorn, indicates the subsolar point's northernmost reach on Earth's surface.

The year's two solstices form a quartet of the astronomical seasons with the year's two equinoxes. The year's March and September equinoxes associate with astronomical spring and astronomical autumn. They designate the containing of the subsolar point on the Equator as the point changes hemispheres. The March equinox registers the subsolar point's northward crossing of the Equator. The September equinox records the subsolar point's southward passage across the Equator.

The first of the pair of 2023 solstices took place Wednesday, June 21, at 14:58 UTC, according to EarthSky's Sunday, Jan. 1, 2023, post, "2023 June solstice: All you need to know." The event announced astronomical summer in the Northern Hemisphere and, oppositely, astronomical winter in the Southern Hemisphere.

The quartet of equinoxes and solstices references astronomical seasons rather than meteorological seasons. Astronomical seasons concern Earth's position with respect to the Sun. Meteorological seasons pertain to Earth's annual temperature cycle, as explained in "Changing seasons," posted on the National Oceanic and Atmospheric Administration's (NOAA) website as an educational resource.

"The Earth’s annual trip around the sun forms the basis for the astronomical calendar in which seasons are defined by two solstices and two equinoxes," NOAA states.

The Earth's 23.5 degree-tilted axis of rotation and the North Pole's orientation away or toward the Sun determine the astronomical dates for the solstices. "At the winter solstice, the North Pole is tilted away from the sun, whereas at the summer solstice, the North Pole is tilted toward the sun," NOAA explains.

The reversal of the seasons in the Southern Hemisphere links with the South Pole. "In the Southern Hemisphere, the seasons are reversed where summer occurs when the South Pole is oriented towards the sun, and winter happens when the South Pole faces away," according to NASA.

The equinoxes take place halfway between the solstices. The March equinox succeeds the December solstice by three months and precedes the June solstice by three months. Then three months elapse between the June solstice and the September equinox and again between the September equinox and the December solstice. The two equinoxes record the alignment of the Sun's path with Earth's Equator.

Graphic of astronomical versus meteorological seasons describes seasons for the Northern Hemisphere in 2022: NOAA Office of Education/Kaleigh Ballantine, via NOAA

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Graphic of Earth's two solstices shows zenithal Sun at Northern Hemisphere's Tropic of Cancer in June and at Southern Hemisphere's Tropic of Capricorn in December; Wednesday, July 1, 2015, graphic by CMG Lee (Cmglee), using Thursday, July 1, 2004, NASA bitmap): Cmglee, NASA, Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Axial_tilt_vs_tropical_and_polar_circles.svg

Graphic of astronomical versus meteorological seasons describes seasons for the Northern Hemisphere in 2022: NOAA Office of Education/Kaleigh Ballantine, via NOAA @ https://www.noaa.gov/education/resource-collections/climate/changing-seasons

For further information:

Byrd, Deborah. "2023 December solstice: All you need to know." EarthSky > Tonight > Astronomy Essentials. June 1, 2023.
Available @ https://earthsky.org/astronomy-essentials/everything-you-need-to-know-december-solstice/

Editors of EarthSky. "2023 June solstice: All you need to know." EarthSky > Tonight > Astronomy Essentials. Jan. 21, 2023.
Available @ https://earthsky.org/astronomy-essentials/everything-you-need-to-know-june-solstice/

Marriner, Derdriu. "2017 Winter Solstice Happens Thursday, Dec. 21, in Northern Hemisphere." Earth and Space News. Wednesdy, Dec. 20, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/12/2017-winter-solstice-happens-thursday.html

Marriner, Derdriu. "2018 Winter Solstice Happens Friday, Dec. 21, in Northern Hemisphere." Earth and Space News. Wednesday, Dec. 19, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/12/2018-winter-solstice-happens-friday-dec.html

Marriner, Derdriu. "2019 Winter Solstice Happens Sunday, Dec. 22, in Northern Hemisphere." Earth and Space News. Wednesday, Dec. 11, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/12/2019-winter-solstice-happens-sunday-dec.html

Marriner, Derdriu. "American Samoa Has Summer Solstice As Rest of U.S. Has Winter Solstice." Earth and Space News. Wednesday, Dec. 12, 2018.
Available @ https://earth-and-space-news.blogspot.com/2018/12/american-samoa-has-summer-solstice-as.html

Marriner, Derdriu. "December Signals Summer Solstice for American Samoa and Jarvis Island." Earth and Space News. Wednesday, Dec. 18, 2019.
Available @ https://earth-and-space-news.blogspot.com/2019/12/december-signals-summer-solstice-for.html

Marriner, Derdriu. "December Solstice Always Occurs at the Same Instant Everywhere on Earth." Earth and Space News. Wednesday, Nov. 30, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/11/december-solstice-always-occurs-at-same.html

Marriner, Derdriu. "December Solstice Opens Astronomical Winter With 2016’s Longest Night." Earth and Space News. Wednesday, Dec. 14, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/12/december-solstice-opens-astronomical.html

Marriner, Derdriu. "December Winter Solstice Opens Northern Hemisphere’s Shortest Season." Earth and Space News. Wednesday, Dec. 21, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/12/december-winter-solstice-opens-northern.html

Marriner, Derdriu. "First 2023 Solstice Happens Wednesday, June 21, at 14:58 UTC." Earth and Space News. Wednesday, June 7, 2023.
Available @ https://earth-and-space-news.blogspot.com/2023/06/first-2023-solstice-happens-wednesday.html

Marriner, Derdriu. "June 21, 2023, Solstice Is Wintry for American Samoa and Jarvis Island." Earth and Space News. Wednesday, June 14, 2023.
Available @ https://earth-and-space-news.blogspot.com/2023/06/june-21-2023-solstice-is-wintry-for.html

Marriner, Derdriu. "Moon Reaches June Apogee 27 Hours After June 21, 2023, Solstice." Earth and Space News. Wednesday, June 21, 2023.
Available @ https://earth-and-space-news.blogspot.com/2023/06/moon-reaches-june-apogee-27-hours-after.html

National Oceanic and Atmospheric Administration. "Changing seasons." National Oceanic and Atmospheric Administration NOAA > Education > Resource collections > Climate.
Available @ https://www.noaa.gov/education/resource-collections/climate/changing-seasons