Summer solstice

From Wikipedia, the free encyclopedia
UT date and time of
equinoxes and solstices on Earth[1]
event equinox solstice equinox solstice
month March June September December
year
day time day time day time day time
2010 20 17:32 21 11:28 23 03:09 21 23:38
2011 20 23:21 21 17:16 23 09:04 22 05:30
2012 20 05:14 20 23:09 22 14:49 21 11:12
2013 20 11:02 21 05:04 22 20:44 21 17:11
2014 20 16:57 21 10:51 23 02:29 21 23:03
2015 20 22:45 21 16:38 23 08:21 22 04:48
2016 20 04:30 20 22:34 22 14:21 21 10:44
2017 20 10:28 21 04:24 22 20:02 21 16:28
2018 20 16:15 21 10:07 23 01:54 21 22:23
2019 20 21:58 21 15:54 23 07:50 22 04:19
2020 20 03:50 20 21:44 22 13:31 21 10:02
The Earth at midnight during the summer solstice in June 2017

The summer solstice (or estival solstice), also known as midsummer, occurs when a planet's rotational axis, or geographical pole on either its northern or its Southern Hemisphere, is most inclined toward the star that it orbits. On the summer solstice, Earth's maximum axial tilt toward the Sun is 23.44°. (Likewise, the Sun's declination from the celestial equator is +23.44° in the Northern Celestial Hemisphere and −23.44° in the Southern Celestial Hemisphere.) This happens twice each year (once in each hemisphere), when the Sun reaches its highest position in the sky as seen from the North or South Pole.

The summer solstice occurs during the hemisphere's summer.[2] This is the northern solstice in the Northern Hemisphere and the southern solstice in the Southern Hemisphere. Depending on the shift of the calendar, the summer solstice occurs some time between June 20 and June 22 in the Northern Hemisphere[3][4] and between December 20 and December 23 each year in the Southern Hemisphere.[5] The same dates in the opposite hemisphere are referred to as the winter solstice.

As seen from a geographic pole, the Sun reaches its highest altitude of the year on the summer solstice. It can be solar noon only along that longitude, which at that moment lies in the direction of the Sun from the pole. For other longitudes, it is not noon. Noon has either passed or has yet to come. Hence the notion of a solstice day is useful. The term is colloquially used like "midsummer" to refer to the day on which solstice occurs. The summer solstice day has the longest period of daylight, except in the polar regions, where daytime remains continuous for 24 hours every day during a period ranging from a few days to six months around the summer solstice.

Distinctions

Diagram of the Earth's seasons as seen from the north. Far left: summer solstice for the Northern Hemisphere. Front right: summer solstice for the Southern Hemisphere.

Although the summer solstice is the longest day of the year for that hemisphere, the dates of earliest sunrise and latest sunset vary by a few days.[6] This is related to the fact that the earth orbits the sun in an ellipse and its orbital speed varies slightly during the year.[7] Although the sun appears at its highest altitude from the viewpoint of an observer in outer space or a terrestrial observer outside tropical latitudes, the highest altitude occurs on a different day for locations in the tropics, specifically the sun is directly overhead (maximum 90 degrees elevation) at the subsolar point. This day occurs twice each year for all locations between the Tropic of Cancer and Tropic of Capricorn because the overhead sun appears to cross a given latitude once before the day of the solstice and once afterward. For example, Lahaina Noon occurs in May and July in Hawaii. See solstice article. For all observers, the apparent position of the noon sun is at its most northerly point on the June solstice and most southerly on the December solstice.

Full moon

2016 was the first time in nearly 70 years that a full moon and the Northern Hemisphere's summer solstice occurred on the same day.[8] The 2016 summer solstice's full moon rose just as the Sun set.[8]

Cultural aspects

Worldwide, interpretation of the event has varied among cultures, but most recognize the event in some way with holidays, festivals, and rituals around that time with themes of religion or fertility.[9] In some regions, the summer solstice is seen as the beginning of summer and the end of spring. In other cultural conventions, the solstice is closer to the middle of summer.[10]

Summer solstice sunset over the Mojave Desert 7:54 p.m. PDT (19:54) June 20, 2016

Solstice is derived from the Latin words sol (sun) and sistere (to stand still).

Date

Date of the northern hemisphere's summer solstice over time. The ~25 drops per century are leap years when the date shifts back one day due to the insertion of February 29.  There was no leap year in 1800 or 1900, which explains why there is no drop those years.

Celebrations

Winter solstice in the Southern Hemisphere

Length of the day on the summer solstice of the north

The following tables contain information on the length of the day on the summer solstice of the northern hemisphere and winter solstice of the southern hemisphere (i.e. June solstice). The data was collected from the website of the Finnish Meteorological Institute on 20 June 2016[11] as well as from certain other websites.[12][13][14][15][16][17][18][19]

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

Fennoscandia and the Baltic states
City Sunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Rovaniemi 24 h
Kem’ 01:44 23:42 21 h 58 min
Reykjavík 2:55 21.6.2016 0:03 21 h 08 min
Trondheim 3:02 23:37 20 h 35 min
Tórshavn 3:36 23:21 19 h 45 min
Petrozavodsk 2:55 22:33 19 h 38 min
Helsinki 3:54 22:49 18 h 55 min
Saint Petersburg 3:35 22:25 18 h 50 min
Oslo 3:53 22:43 18 h 49 min
Tallinn 4:03 22:42 18 h 39 min
Stockholm 3:30 22:07 18 h 37 min
Riga 4:29 22:21 17 h 52 min
Copenhagen 4:25 21:57 17 h 32 min
Vilnius 4:41 21:59 17 h 17 min
Europe
City Sunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Edinburgh 4:26 22:02 17 h 36 min
Moscow 3:44 21:17 17 h 33 min
Berlin 4:43 21:33 16 h 49 min
London 4:43 21:21 16 h 38 min
Paris 5:46 21:57 16 h 10 min
Rome 5:34 20:48 15 h 13 min
Madrid 6:44 21:48 15 h 03 min
Lisbon 6:11 21:04 14 h 52 min
Athens 6:02 20:50 14 h 48 min
Africa
City Sunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Cairo 4:54 18:59 14 h 04 min
Dakar 6:41 19:41 12 h 59 min
Addis Ababa 6:07 18:46 12 h 38 min
Nairobi 6:32 18:35 12 h 02 min
Kinshasa 6:04 17:56 11 h 52 min
Dar es Salaam 6:32 18:16 11 h 43 min
Luanda 6:20 17:56 11 h 36 min
Jamestown 6:49 17:59 11 h 10 min
Antananarivo 6:21 17:21 10 h 59 min
Windhoek 6:30 17:15 10 h 44 min
Johannesburg 6:54 17:24 10 h 29 min
Cape Town 7:51 17:44 9 h 53 min
Middle East
City Sunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Tehran 5:48 20:23 14 h 34 min
Beirut 5:27 19:52 14 h 24 min
Baghdad 4:53 19:14 14 h 21 min
Jerusalem 5:33 19:47 14 h 13 min
Riyadh 5:04 18:44 13 h 39 min
Muscat 5:19 18:55 13 h 35 min
Sana'a 5:33 18:35 13 h 02 min
Americas
City Sunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Fairbanks 2:57 21.6. 00:47 21 h 49 min
Nuuk 2:53 21.6. 00:03 21 h 09 min
Iqaluit 2:11 23:00 20 h 49 min
Anchorage 4:20 23:41 19 h 21 min
Kodiak 5:07 23:14 18 h 06 min
Sitka 4:06 22:00 17 h 54 min
Unalaska 6:34 23:41 17 h 06 min
Vancouver 5:06 21:21 16 h 14 min
Seattle 5:11 21:10 15 h 59 min
Ottawa 5:14 20:54 15 h 40 min
New York 5:24 20:30 15 h 05 min
Washington, D.C. 5:42 20:36 14 h 53 min
Los Angeles 5:42 20:07 14 h 25 min
Miami 6:30 20:14 13 h 44 min
Havana 6:44 20:17 13 h 33 min
Honolulu 5:50 19:16 13 h 25 min
Mexico City 6:59 20:17 13 h 18 min
Managua 5:21 18:11 12 h 50 min
Bogotá 5:46 18:09 12 h 23 min
Quito 6:12 18:19 12 h 06 min
Lima 6:27 17:52 11 h 24 min
Rio de Janeiro 6:32 17:16 10 h 43 min
Santiago 7:46 17:42 9 h 56 min
Buenos Aires 8:00 17:50 9 h 49 min
Ushuaia 9:58 17:11 7 h 12 min
Asia and Oceania
City Sunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Provideniya 0:52 22:16 21 h 23 min
Magadan 3:37 22:19 18 h 41 min
Petropavlovsk 4:58 21:55 16 h 56 min
Khabarovsk 4:57 21:04 16 h 07 min
Ulaanbaatar 5:52 21:54 16 h 01 min
Vladivostok 5:32 20:55 15 h 22 min
Beijing 4:45 19:46 15 h 00 min
Seoul 5:11 19:56 14 h 46 min
Tokyo 4:25 19:00 14 h 34 min
Shanghai 4:50 19:01 14 h 10 min
Lhasa 6:55 20:58 14 h 03 min
Delhi 5:23 19:21 13 h 58 min
Kathmandu 5:08 19:02 13 h 53 min
Taipei 5:04 18:46 13 h 41 min
Hong Kong 5:39 19:09 13 h 30 min
Manila 5:27 18:27 12 h 59 min
Bangkok 5:51 18:47 12 h 56 min
Singapore 7:00 19:12 12 h 11 min
Jakarta 6:01 17:47 11 h 45 min
Darwin 7:06 18:29 11 h 23 min
Papeete 6:27 17:32 11 h 04 min
Sydney 6:59 16:53 9 h 53 min
Auckland 7:33 17:11 9 h 37 min
Melbourne 7:35 17:07 9 h 32 min
Dunedin 8:19 16:59 8 h 39 min

See also

References

  1. ^ United States Naval Observatory (21 September 2015). "Earth's Seasons: Equinoxes, Solstices, Perihelion, and Aphelion, 2000-2025". Retrieved 9 December 2015. 
  2. ^ http://www.metoffice.gov.uk/learning/learn-about-the-weather/how-weather-works/when-does-spring-start
  3. ^ "The June Solstice". Time and Date AS. Retrieved 2012-01-30. 
  4. ^ "Solstice (astronomy)". Britannica Online Encyclopedia. Retrieved 2011-06-20. 
  5. ^ "December Solstice". Time and Date AS. Retrieved 2012-01-30. 
  6. ^ "US Naval Observatory: Sunrise and Sunset Times Near the Solstices". Retrieved 21 June 2017. 
  7. ^ "The Long Story (USNO explanation)". Retrieved 21 June 2017. 
  8. ^ a b "Full Moon and Summer Solstice coincide on the same day". The Old Farmer's Almanac. Retrieved 21 June 2016. 
  9. ^ "Summer solstice celebrations of Christianity, Judaism, Neopaganism, etc". Religioustolerance.org. Retrieved 2011-06-20. 
  10. ^ http://weather.about.com/od/climatechange/fl/Astronomical-vs-Meteorological-Seasons.htm
  11. ^ "Paikallissää Helsinki" [‘Local weather in Helsinki’] (in Finnish). Finnish Meteorological Institute. 2016-06-20. Retrieved 2016-06-20. 
  12. ^ "Jamestown, Saint Helena". Retrieved 2016-06-22. 
  13. ^ "Fairbanks". Retrieved 2016-06-22. 
  14. ^ "Nuuk". Retrieved 2016-06-22. 
  15. ^ "Iqaluit". Retrieved 2016-06-22. 
  16. ^ "Sitka". Retrieved 2016-06-22. 
  17. ^ "Unalaska". Retrieved 2016-06-22. 
  18. ^ "Provideniya". Retrieved 2016-06-22. 
  19. ^ "Katmandu". Retrieved 2016-06-22. 

External links

  • Table of dates/times from 1600–2400
Retrieved from "https://en.wikipedia.org/w/index.php?title=Summer_solstice&oldid=806420783"
This content was retrieved from Wikipedia : http://en.wikipedia.org/wiki/Summer_solstice
This page is based on the copyrighted Wikipedia article "Summer solstice"; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA