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

The December solstice, also known as the southern solstice, is the solstice that occurs each December – typically on 21 December, but may vary by one day in either direction according to the Gregorian calendar. In the Northern Hemisphere, the December solstice is the winter solstice (the day with the shortest period of daylight), whilst in the Southern Hemisphere it is the summer solstice (the day with the longest period of daylight).

The solstice also marks the changing of seasons in many countries. 21 December is the first day of winter (in the Northern Hemisphere) and the first day of summer (in the Southern Hemisphere).

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 AD 2000, in the range of 49 minutes 30 seconds to 50 minutes in excess of 365 days 5 hours. This is longer than the mean year of the Gregorian calendar, which has an excess time of 49 minutes and 12 seconds. Since 2000, it has been growing shorter. In 4000, the excess time will be 48 minutes 52 seconds, and, in 10000, 46 minutes 45 seconds.^[7]

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.^{[8][9][10][11][12][13]}

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

The Nordic countries, Russia, and the Baltic states
City	Sunrise 21 Dec 2022	Sunset 21 Dec 2022	Length of the day
Murmansk	—	—	0 min
Apatity	—	—	0 min
Bodø	11:35	12:24	49 min
Rovaniemi	11:07	13:22	2 h 15 min
Luleå	9:54	13:03	3 h 9 min
Reykjavík	11:21	15:29	4 h 8 min
Trondheim	10:01	14:31	4 h 30 min
Tórshavn	9:50	14:59	5 h 9 min
Helsinki	9:23	15:12	5 h 49 min
Oslo	9:17	15:11	5 h 54 min
Tallinn	9:17	15:20	6 h 3 min
Stockholm	8:43	14:47	6 h 4 min
Riga	8:59	15:43	6 h 44 min
Copenhagen	8:36	15:38	7 h 2 min
Vilnius	8:39	15:53	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
Kyiv	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

Middle East
City	Sunrise 22 Dec 2015	Sunset 22 Dec 2015	Length of the day
Tehran	7:10	16:55	9 h 44 min
Beirut	6:39	16:33	9 h 54 min
Baghdad	7:02	16:59	9 h 57 min
Jerusalem	6:35	16:39	10 h 04 min
Manama	6:21	16:51	10 h 30 min
Doha	6:15	16:49	10 h 34 min
Dubai	7:00	17:34	10 h 34 min
Riyadh	6:32	17:10	10 h 37 min
Muscat	6:43	17:23	10 h 41 min
Sana'a	6:25	17:38	11 h 13 min

Americas
City	Sunrise 22 Dec 2015	Sunset 22 Dec 2015	Length of the day
Inuvik	—	—	0 h
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
Salt Lake City	7:48	17:03	9 h 14 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-Pacific
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
Dunedin	5:43	21:28	15 h 44 min
Invercargill	5:50	21:39	15 h 48 min

See also

References

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