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). The summer solstice is the day with the longest period of daylight and shortest night of the year in that hemisphere, 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.
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 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 summer's beginning.
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]
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 Julian calendar of the Roman Empire, the date of the summer solstice was 24 June,[12] and Marcus Terentius Varro wrote in the 1st century BC that the Romans saw this as the middle of summer.[13] The Julian calendar had a flaw in that the solstices and equinoxes gradually fell on earlier dates. At the First Council of Nicaea (325), the Christian Church set the date of the spring equinox to 21 March, for the purpose of calculating Easter. This also brought the date of the summer solstice forward to 20 June.[14]
Elsewhere in northern Europe, traditionally the summer solstice is also seen as the middle of summer and it was reckoned as the night of 23–24 June.[16] 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.[17] In Sweden, midsummer is one of the year's major holidays when the country closes down as much as during Christmas.
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 +.
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
↑ Also aestival solstice in British English. From Latin aestīvus, 'summer'.
↑ O'Neill, William Matthew (1976). Time and the Calendars. Manchester University Press. p.85.
↑ Forsythe, Gary (2012). Time in Roman Religion: One Thousand Years of Religious History. Routledge. pp.123, 182. Varro places the equinoxes and solstices at the midpoints of the seasons ... His dating for the beginnings of the four seasons are as follows: February 7 for spring, May 9 for summer, August 11 for autumn, and November 10 for winter.
↑ Ó Carragáin, Éamonn (2005). Ritual and the Rood: Liturgical Images and the Old English Poems of the Dream of the Rood Tradition. University of Toronto Press. pp.106–107.
↑ Karasawa, Kazutomo (2015). The Old English Metrical Calendar (Menologium). Anglo-Saxon Texts. Vol.12. Cambridge: Boydell & Brewer. pp.36–37, 106. ISBN978-1-84384-409-9.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
