Summer 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
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
2026 20 14:46 21 08:25 23 00:06 21 20:50

The summer solstice, also known as estival solstice[3] or midsummer, occurs when one of Earth's poles has its maximum tilt toward the Sun. It happens twice yearly, once in each hemisphere (Northern and Southern). For that hemisphere, the summer solstice is when the Sun reaches its highest position in the sky (for areas outside of the tropics) and is the day with the longest period of daylight. Within the Arctic circle (for the northern hemisphere) or Antarctic circle (for the southern hemisphere), there is continuous daylight around the summer solstice. On the summer solstice, Earth's maximum axial tilt toward the Sun is 23.44°.[4] Likewise, the Sun's declination from the celestial equator is 23.44°.

Earth during the summer solstice in June 2017

The summer solstice occurs during summer.[5] This is the June solstice in the Northern Hemisphere and the December solstice in the Southern Hemisphere. Depending on the shift of the calendar, the summer solstice occurs sometime between June 20 and June 22 in the Northern Hemisphere[6][7] and between December 20 and December 23 in the Southern Hemisphere.[8] The same dates in the opposite hemisphere are referred to as the winter solstice.

Since prehistory, the summer solstice has been seen as a significant time of year in many cultures, and has been marked by festivals and rituals. Traditionally, in many temperate regions (especially Europe), the summer solstice is seen as the middle of summer and referred to as "midsummer". Today, however, in some countries and calendars it is seen as the beginning of summer.

DistinctionsEdit

 
Diagram of 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.[9] This is because Earth orbits the Sun in an ellipse, and its orbital speed varies slightly during the year.[4]

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 certain locations in the tropics, specifically those where 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 moonEdit

The year 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.[10] The 2016 summer solstice's full moon rose just as the Sun set.[11]

Cultural aspectsEdit

The significance given to the summer solstice 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.[12] For example, in Sweden, midsummer is one of the year's major holidays when the country closes down as much as during Christmas. 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.[13]

 
Summer solstice sunset over the Mojave Desert 7:54 p.m. PDT (19:54) June 20, 2016
 
Longreach, Queensland at mid-day of Summer Solstice (with respect to southern hemisphere) or Winter Solstice (with respect to Northern hemisphere), 22 December 2019. The town is on the Tropic of Capricorn (Shadow directly below the sign)

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

DateEdit

CelebrationsEdit

Winter solstice in the Southern HemisphereEdit

Length of the day on the summer solstice of the northEdit

The following tables contain information on the length of the day on the 20th June, close to 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[14] as well as from certain other websites.[15][16][17][18][19][20][21][22][23][24][25]

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
  Murmansk 24 h
  Bodø 24 h
  Rovaniemi 24 h
  Luleå 1:00 21.6.2016 0:05 23 h 04 min
  Kem’ 1:44 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
  Warsaw 4:14 21:00 16 h 46 min
  London 4:43 21:21 16 h 38 min
  Kyiv 4:46 21:12 16 h 26 min
  Paris 5:46 21:57 16 h 10 min
  Vienna 4:53 20:58 16 h 04 min
  Budapest 4:46 20:44 15 h 58 min
  Zürich 5:29 21:25 15 h 56 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
  Tenerife 7:08 21:05 13 h 57 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
  Manama 4:45 18:32 13 h 46 min
  Doha 4:44 18:26 13 h 42 min
  Dubai 5:29 19:11 13 h 42 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
  Inuvik 24 h
  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
  Edmonton 5:04 22:07 17 h 02 min
  Winnipeg 5:19 21:40 16 h 21 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
  Toronto 5:35 21:02 15 h 26 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
  La Paz 6:59 18:08 11 h 08 min
  Rio de Janeiro 6:32 17:16 10 h 43 min
  São Paulo 6:47 17:28 10 h 40 min
  Porto Alegre 7:20 17:32 10 h 12 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

Length of day increases from the equator towards the North Pole in the Northern Hemisphere in June (around the summer solstice there), but decreases towards the South Pole in the Southern Hemisphere at the time of the southern winter solstice.

See alsoEdit

ReferencesEdit

  1. ^ United States Naval Observatory (January 4, 2018). "Earth's Seasons and Apsides: Equinoxes, Solstices, Perihelion, and Aphelion". Archived from the original on 24 Dec 2017. Retrieved September 18, 2018.
  2. ^ "Solstices and Equinoxes: 2001 to 2100". AstroPixels.com. February 20, 2018. Retrieved December 21, 2018.
  3. ^ From the Latin aestīvus = summer.
  4. ^ a b "The Long Story (USNO explanation)". Archived from the original on 18 June 2017. Retrieved 21 June 2017.
  5. ^ "When does spring start?". Archived from the original on 2016-11-25. Retrieved 2016-11-12.
  6. ^ "The June Solstice". Time and Date AS. Archived from the original on 2012-02-04. Retrieved 2012-01-30.
  7. ^ "Solstice (astronomy)". Britannica Online Encyclopedia. Archived from the original on 2011-06-25. Retrieved 2011-06-20.
  8. ^ "December Solstice". Time and Date AS. Archived from the original on 2012-01-18. Retrieved 2012-01-30.
  9. ^ "US Naval Observatory: Sunrise and Sunset Times Near the Solstices". Archived from the original on 18 June 2017. Retrieved 21 June 2017.
  10. ^ "Full Moon and Winter Solstice coincide on the same day". The Old Farmer's Almanac. Archived from the original on 23 June 2016. Retrieved 21 June 2016.
  11. ^ "Full Moon and Summer Solstice coincide on the same day". The Old Farmer's Almanac. Archived from the original on 22 June 2016. Retrieved 21 June 2016.
  12. ^ "Summer solstice celebrations of Christianity, Judaism, Neopaganism, etc". Religioustolerance.org. Archived from the original on 2011-06-28. Retrieved 2011-06-20.
  13. ^ "The Astronomical vs. Meteorological Seasons". Archived from the original on 2016-11-14. Retrieved 2016-11-13.
  14. ^ "Paikallissää Helsinki" [‘Local weather in Helsinki’] (in Finnish). Finnish Meteorological Institute. 2016-06-20. Retrieved 2016-06-20.
  15. ^ "Jamestown, Saint Helena". Retrieved 2016-06-22.
  16. ^ "Fairbanks". Retrieved 2016-06-22.
  17. ^ "Nuuk". Retrieved 2016-06-22.
  18. ^ "Iqaluit". Retrieved 2016-06-22.
  19. ^ "Sitka". Retrieved 2016-06-22.
  20. ^ "Unalaska". Retrieved 2016-06-22.
  21. ^ "Provideniya". Retrieved 2016-06-22.
  22. ^ "Katmandu". Retrieved 2016-06-22.
  23. ^ "Edmonton, Canada". Retrieved 2016-06-22.
  24. ^ "Inuvik, Canada". Retrieved 2020-12-19.
  25. ^ "Winnipeg, Canada". Retrieved 2021-07-31.

External linksEdit