Solsticial

Solsticial is an adjective used to refer to the solstice or to things occurring at the solstices. The word is formed from solstice, which derives from Latin solstitium, from sol “sun” and sistere “to stand still.” In modern English the more common form is solstitial; solsticial appears occasionally in scholarly or historical texts.

In astronomy, the solstices occur roughly on June 21 (northern summer solstice) and December 21 (northern winter solstice); at these times solar declination is about +23.44° and -23.44°. The term “solsticial” may be used to describe conditions near these times, such as solsticial daylight patterns or solsticial winds, though such phrases are uncommon.

In cultural contexts, solsticial events have long informed calendars and rituals in various cultures, with midsummer and midwinter festivals. In the southern hemisphere, the solstices occur opposite to those in the northern hemisphere, reflecting the seasonal swap characteristic of that region.

See also: solstice, solstitial.