Summer solstice

UT date and time of
equinoxes and solstices on Earth[1][2]
eventequinoxsolsticeequinoxsolstice
monthMarch[3]June[4]September[5]December[6]
yeardaytimedaytimedaytimedaytime
20192021:582115:542307:502204:19
20202003:502021:432213:312110:03
20212009:372103:322219:212115:59
20222015:332109:142301:042121:48
20232021:252114:582306:502203:28
20242003:072020:512212:442109:20
20252009:022102:422218:202115:03
20262014:462108:252300:062120:50
20272020:252114:112306:022202:43
20282002:172020:022211:452108:20
20292008:012101:482217:372114:14

The summer solstice or estival solstice[i] 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 the day with the longest period of daylight and shortest night of the year, when the Sun is at its highest position in the sky. At either pole there is continuous daylight at the time of its summer solstice. The opposite event is the winter solstice.

Earth during the summer solstice in June 2017

The summer solstice occurs during the hemisphere's summer. In the Northern Hemisphere, this is the June solstice (20 or 21 June) and in the Southern Hemisphere, this is the December solstice (21 or 22 of December). Since prehistory, the summer solstice has been a significant time of year in many cultures, and has been marked by festivals and rituals. Traditionally, in temperate regions (especially Europe), the summer solstice is seen as the middle of summer and referred to as midsummer; although today in some countries and calendars it is seen as the beginning of summer.

On the summer solstice, Earth's maximum axial tilt toward the Sun is 23.44°.[7] Likewise, the Sun's declination from the celestial equator is 23.44°.

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.[8] This is because Earth orbits the Sun in an ellipse, and its orbital speed varies slightly during the year.[7]

Culture

The solstice being celebrated at Stonehenge in England

There is evidence that the summer solstice has been culturally important since the Neolithic era. Many ancient monuments in Europe especially, as well as parts of the Middle East, Asia and the Americas, are aligned with the sunrise or sunset on the summer solstice (see archaeoastronomy).[9][10] The significance of 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 fertility.[11] In the Roman Empire, the traditional date of the summer solstice was 24 June.[12] In Germanic-speaking cultures, the time around the summer solstice is called 'midsummer'. Traditionally in northern Europe midsummer was reckoned as the night of 23–24 June, with summer beginning on May Day.[13] The summer solstice continues to be seen as the middle of summer in many European cultures, but in some cultures or calendars it is seen as summer's beginning.[14] In Sweden, midsummer is one of the year's major holidays when the country closes down as much as during Christmas.

Observances

Traditional festivals
Modern observances

Length of the day on northern summer solstice

The following tables contain information on the length of the day on 20 June 2016, close to the summer solstice of the Northern Hemisphere and winter solstice of the Southern Hemisphere. The data was collected from the website of the Finnish Meteorological Institute[15] as well as from certain other websites.[16][17][18][19][20][21][22][23][24][25][26]

The data is arranged geographically and within the tables from the longest day to the shortest one. Times that occur the next day (21 June) are marked with +.

Fennoscandia and the Baltic states
CitySunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Murmansk24 h
Apatity24 h
Bodø24 h
Rovaniemi24 h
Luleå1:000:05+23 h 04 min
Arkhangelsk1:3423:0421 h 30 min
Reykjavík2:550:03+21 h 08 min
Trondheim3:0223:3720 h 35 min
Tórshavn3:3623:2119 h 45 min
Petrozavodsk2:5522:3319 h 38 min
Helsinki3:5422:4918 h 55 min
Saint Petersburg3:3522:2518 h 50 min
Oslo3:5322:4318 h 49 min
Tallinn4:0322:4218 h 39 min
Stockholm3:3022:0718 h 37 min
Riga4:2922:2117 h 52 min
Copenhagen4:2521:5717 h 32 min
Vilnius4:4121:5917 h 17 min
Europe
CitySunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Edinburgh4:2622:0217 h 36 min
Moscow3:4421:1717 h 33 min
Berlin4:4321:3316 h 49 min
Warsaw4:1421:0016 h 46 min
London4:4321:2116 h 38 min
Kyiv4:4621:1216 h 26 min
Paris5:4621:5716 h 10 min
Vienna4:5320:5816 h 04 min
Budapest4:4620:4415 h 58 min
Zürich5:2921:2515 h 56 min
Rome5:3420:4815 h 13 min
Madrid6:4421:4815 h 03 min
Lisbon6:1121:0414 h 52 min
Athens6:0220:5014 h 48 min
Africa
CitySunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Cairo4:5418:5914 h 04 min
Tenerife7:0821:0513 h 57 min
Dakar6:4119:4112 h 59 min
Addis Ababa6:0718:4612 h 38 min
Nairobi6:3218:3512 h 02 min
Kinshasa6:0417:5611 h 52 min
Dar es Salaam6:3218:1611 h 43 min
Luanda6:2017:5611 h 36 min
Jamestown6:4917:5911 h 10 min
Antananarivo6:2117:2110 h 59 min
Windhoek6:3017:1510 h 44 min
Johannesburg6:5417:2410 h 29 min
Cape Town7:5117:449 h 53 min
Middle East
CitySunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Tehran5:4820:2314 h 34 min
Beirut5:2719:5214 h 24 min
Baghdad4:5319:1414 h 21 min
Jerusalem5:3319:4714 h 13 min
Manama4:4518:3213 h 46 min
Doha4:4418:2613 h 42 min
Dubai5:2919:1113 h 42 min
Riyadh5:0418:4413 h 39 min
Muscat5:1918:5513 h 35 min
Sana'a5:3318:3513 h 02 min
Americas
CitySunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Inuvik24 h
Fairbanks2:570:47+21 h 49 min
Nuuk2:530:03+21 h 09 min
Iqaluit2:1123:0020 h 49 min
Anchorage4:2023:4119 h 21 min
Kodiak5:0723:1418 h 06 min
Sitka4:0622:0017 h 54 min
Unalaska6:3423:4117 h 06 min
Edmonton5:0422:0717 h 02 min
Winnipeg5:1921:4016 h 21 min
Vancouver5:0621:2116 h 14 min
Seattle5:1121:1015 h 59 min
Ottawa5:1420:5415 h 40 min
Toronto5:3521:0215 h 26 min
New York5:2420:3015 h 05 min
Washington, D.C.5:4220:3614 h 53 min
Los Angeles5:4220:0714 h 25 min
Miami6:3020:1413 h 44 min
Havana6:4420:1713 h 33 min
Honolulu5:5019:1613 h 25 min
Mexico City6:5920:1713 h 18 min
Kingston5:3218:4513 h 13 min
Bridgetown5:3318:2712 h 54 min
Managua5:2118:1112 h 50 min
Port of Spain5:4518:3012 h 45 min
Georgetown5:3818:0912 h 31 min
Bogotá5:4618:0912 h 23 min
Quito6:1218:1912 h 06 min
Lima6:2717:5211 h 24 min
La Paz6:5918:0811 h 08 min
Rio de Janeiro6:3217:1610 h 43 min
São Paulo6:4717:2810 h 40 min
Porto Alegre7:2017:3210 h 12 min
Santiago7:4617:429 h 56 min
Buenos Aires8:0017:509 h 49 min
Ushuaia9:5817:117 h 12 min
Asia and Oceania
CitySunrise
20 June 2016
Sunset
20 June 2016
Length of the day
Provideniya0:5222:1621 h 23 min
Magadan3:3722:1918 h 41 min
Petropavlovsk4:5821:5516 h 56 min
Khabarovsk4:5721:0416 h 07 min
Ulaanbaatar5:5221:5416 h 01 min
Vladivostok5:3220:5515 h 22 min
Beijing4:4519:4615 h 00 min
Seoul5:1119:5614 h 46 min
Tokyo4:2519:0014 h 34 min
Shanghai4:5019:0114 h 10 min
Lhasa6:5520:5814 h 03 min
Delhi5:2319:2113 h 58 min
Kathmandu5:0819:0213 h 53 min
Taipei5:0418:4613 h 41 min
Hong Kong5:3919:0913 h 30 min
Manila5:2718:2712 h 59 min
Bangkok5:5118:4712 h 56 min
Singapore7:0019:1212 h 11 min
Jakarta6:0117:4711 h 45 min
Darwin7:0618:2911 h 23 min
Papeete6:2717:3211 h 04 min
Sydney6:5916:539 h 53 min
Auckland7:3317:119 h 37 min
Melbourne7:3517:079 h 32 min
Dunedin8:1916:598 h 39 min

The 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.

Notes

References

External links