December solstice

The December solstice, is the solstice that occurs each December – typically on Dec 21, and can vary ± 1 day according to the Gregorian calendar. In the Northern Hemisphere, the December solstice is the winter solstice, whilst in the Southern Hemisphere it is the summer solstice. It is also known as the southern solstice.

UT date and time of
equinoxes and solstices on Earth[1][2]

event	equinox		solstice		equinox		solstice
month	March		June		September		December
year
	day	time	day	time	day	time	day	time
2015	20	22:45	21	16:38	23	08:20	22	04:48
2016	20	04:31	20	22:35	22	14:21	21	10:45
2017	20	10:29	21	04:25	22	20:02	21	16:29
2018	20	16:15	21	10:07	23	01:54	21	22:22
2019	20	21:58	21	15:54	23	07:50	22	04:19
2020	20	03:50	20	21:43	22	13:31	21	10:03
2021	20	09:37	21	03:32	22	19:21	21	15:59
2022	20	15:33	21	09:14	23	01:04	21	21:48
2023	20	21:25	21	14:58	23	06:50	22	03:28
2024	20	03:07	20	20:51	22	12:44	21	09:20
2025	20	09:02	21	02:42	22	18:20	21	15:03

Illumination of Earth by the Sun on the day of the December solstice

Dates

Recent, past, and future dates and times, in Universal Time, of the December solstice are:[3]

Date	time
2000-12-21	13:37
2001-12-21	19:21
2002-12-22	01:14
2003-12-22	07:04
2004-12-21	12:42
2005-12-21	18:35
2006-12-22	00:22
2007-12-22	06:08
2008-12-21	12:04
2009-12-21	17:47
2010-12-21	23:38
2011-12-22	05:30
2012-12-21	11:12
2013-12-21	17:11
2014-12-21	23:03
2015-12-22	04:48
2016-12-21	10:44
2017-12-21	16:28
2018-12-21	22:23
2019-12-22	04:19
2020-12-21	10:02

Solar year

The December solstice solar year is the solar year based on the December solstice. It is thus the length of time between adjacent December solstices.

The length of the December solstice year has been relatively stable between 6000 BC and 2000 at 49:30 (minutes:seconds) to 50:00 in excess of 365 days and 5 hours. After 2000 it is getting shorter. In 4000 the excess time will be 48:52 and in 10000 46:45.[4]

The length of the day near the December solstice

The following tables contain information on the length of the day on December 22nd, close to the winter solstice of the Northern Hemisphere and the summer solstice of the Southern Hemisphere (i.e. December solstice). The data was collected from the website of the Finnish Meteorological Institute on 22 December 2015, as well as from certain other websites.[5][6][7][8][9]

The data is arranged geographically and within the tables from the shortest day to the longest one.

The Nordic countries and the Baltic states
City	Sunrise 22 Dec 2015	Sunset 22 Dec 2015	Length of the day
Murmansk	—	—	0 h
Bodø	11:36	12:25	0 h 49 min
Rovaniemi	11:08	13:22	2 h 14 min
Luleå	9:55	13:04	3 h 08 min
Reykjavík	11:22	15:29	4 h 07 min
Trondheim	10:01	14:31	4 h 30 min
Tórshavn	9:51	14:59	5 h 08 min
Helsinki	9:24	15:13	5 h 49 min
Oslo	9:18	15:12	5 h 54 min
Tallinn	9:17	15:20	6 h 02 min
Stockholm	8:43	14:48	6 h 04 min
Riga	9:00	15:43	6 h 43 min
Copenhagen	8:37	15:38	7 h 01 min
Vilnius	8:40	15:54	7 h 14 min

Europe
City	Sunrise 22 Dec 2015	Sunset 22 Dec 2015	Length of the day
Edinburgh	8:42	15:40	6 h 57 min
Moscow	8:57	15:58	7 h 00 min
Berlin	8:15	15:54	7 h 39 min
Warsaw	7:43	15:25	7 h 42 min
London	8:04	15:53	7 h 49 min
Kiev	7:56	15:56	8 h 00 min
Paris	8:41	16:56	8 h 14 min
Vienna	7:42	16:03	8 h 20 min
Budapest	7:28	15:55	8 h 26 min
Rome	7:34	16:42	9 h 07 min
Madrid	8:34	17:51	9 h 17 min
Lisbon	7:51	17:18	9 h 27 min
Athens	7:37	17:09	9 h 31 min

Africa
City	Sunrise 22 Dec 2015	Sunset 22 Dec 2015	Length of the day
Cairo	6:47	16:59	10 h 12 min
Tenerife	7:53	18:13	10 h 19 min
Dakar	7:30	18:46	11 h 15 min
Addis Ababa	6:35	18:11	11 h 36 min
Nairobi	6:25	18:37	12 h 11 min
Kinshasa	5:45	18:08	12 h 22 min
Dar es Salaam	6:05	18:36	12 h 31 min
Luanda	5:46	18:24	12 h 38 min
Antananarivo	5:10	18:26	13 h 16 min
Windhoek	6:04	19:35	13 h 31 min
Johannesburg	5:12	18:59	13 h 47 min
Cape Town	5:32	19:57	14 h 25 min

Americas
City	Sunrise 22 Dec 2015	Sunset 22 Dec 2015	Length of the day
Fairbanks	10:58	14:40	3 h 41 min
Nuuk	10:22	14:28	4 h 06 min
Anchorage	10:14	15:42	5 h 27 min
Edmonton	8:48	16:15	7 h 27 min
Vancouver	8:05	16:16	8 h 11 min
Seattle	7:55	16:20	8 h 25 min
Ottawa	7:39	16:22	8 h 42 min
Toronto	7:48	16:43	8 h 55 min
New York City	7:16	16:32	9 h 15 min
Washington, D.C.	7:23	16:49	9 h 26 min
Los Angeles	6:55	16:48	9 h 53 min
Dallas	7:25	17:25	9 h 59 min
Miami	7:03	17:35	10 h 31 min
Honolulu	7:04	17:55	10 h 50 min
Mexico City	7:06	18:03	10 h 57 min
Managua	6:01	17:26	11 h 24 min
Bogotá	5:59	17:50	11 h 51 min
Quito	6:08	18:16	12 h 08 min
Recife	5:00	17:35	12 h 35 min
Lima	5:41	18:31	12 h 50 min
La Paz	5:57	19:04	13 h 06 min
Rio de Janeiro	6:04	19:37	13 h 33 min
São Paulo	6:17	19:52	13 h 35 min
Porto Alegre	6:20	20:25	14 h 05 min
Santiago	6:29	20:52	14 h 22 min
Buenos Aires	5:37	20:06	14 h 28 min
Ushuaia	4:51	22:11	17 h 19 min

Asia and Oceania
City	Sunrise 22 Dec 2015	Sunset 22 Dec 2015	Length of the day
Magadan	8:54	14:55	6 h 00 min
Petropavlovsk	9:36	17:10	7 h 33 min
Khabarovsk	8:48	17:07	8 h 18 min
Ulaanbaatar	8:39	17:02	8 h 22 min
Vladivostok	8:40	17:40	8 h 59 min
Beijing	7:32	16:52	9 h 20 min
Seoul	7:44	17:17	9 h 34 min
Tokyo	6:47	16:31	9 h 44 min
Shanghai	6:48	16:55	10 h 07 min
Lhasa	8:46	19:01	10 h 14 min
Delhi	7:09	17:28	10 h 19 min
Hong Kong	6:58	17:44	10 h 46 min
Manila	6:16	17:32	11 h 15 min
Bangkok	6:36	17:55	11 h 19 min
Singapore	7:01	19:04	12 h 03 min
Jakarta	5:36	18:05	12 h 28 min
Denpasar	5:58	18:36	12 h 37 min
Darwin	6:19	19:10	12 h 51 min
Papeete	5:21	18:32	13 h 10 min
Brisbane	4:49	18:42	13 h 52 min
Perth	5:07	19:22	14 h 14 min
Sydney	5:41	20:05	14 h 24 min
Auckland	5:58	20:39	14 h 41 min
Melbourne	5:54	20:42	14 h 47 min
Invercargill	5:50	21:39	15 h 48 min

Human culture

Calendars

Gregorian calendar

Iranian (Persian) calendar

The figures in the charts show the differences between the Gregorian calendar and Persian Jalāli calendar in reference to the actual yearly time of the Southern solstice. The error shifts by slightly less than 1/4-day per year; in the Gregorian calendar it is corrected by a leap year every 4th year, omitting three such corrections in every 400 years, so that the average length of a calendar year is 365 97/400 days; while in the Persian calendar every eighth leap-cycle is extended to 5 years, making the average 365 8/33 days, shorter than the Gregorian average by one day every 13200 years.

The date of the solstice is not the same as the date of the latest sunrise and both are not the same as the date of earliest sunset. Because the Earth is moving along its solar orbital path, for each solar day the Earth has to do more than one full rotation. Because the Earth's orbit is elliptical, the speed at which the Earth moves along its orbit varies. Consequently, solar days are not the same length throughout the year. "Mean time" is our way of modifying this, for our convenience, making each day the same length, i.e. 24 hours. The maximum correction (see Equation of Time) is ± 15 minutes to the mean but its value changes quite rapidly around the solstices. If solar time were used rather than mean time, the latest sunrise and earliest sunset and therefore also the shortest day would all be at the December solstice in the northern hemisphere; the opposite would be true in the southern hemisphere, with the earliest sunrise, latest sunset, and longest day.

Commemorations

See also: Winter solstice

• Christmas
• Dies Natalis Solis Invicti
• Brumalia
• Dongzhi Festival

References

1. United States Naval Observatory (4 January 2018). "Earth's Seasons and Apsides: Equinoxes, Solstices, Perihelion, and Aphelion". Retrieved 18 September 2018.
2. "Solstices and Equinoxes: 2001 to 2100". AstroPixels.com. 20 February 2018. Retrieved 21 December 2018.
3. Earth's Seasons — Naval Oceanography Portal
4. Bromberg, Irv. "Solar Year Length Variations on Earth" (PDF). University of Toronto, Canada. Retrieved 21 December 2012.
5. "Paikallissää Helsinki" [‘Local weather in Helsinki’] (in Finnish). Finnish Meteorological Institute. 22 December 2015. Retrieved 22 December 2015.
6. "Perth, Australia". Retrieved 22 December 2015.
7. "São Paulo, Brazil". Retrieved 22 December 2015.
8. "Denpasar, Indonesia". Retrieved 22 December 2015.
9. "Edmonton, Canada". Retrieved 21 December 2019.