First day of summer (Iceland)
{{Short description|Annual public holiday in Iceland}}
{{About|the Iceland holiday|the day on which summer begins|Season#Reckoning}}
{{Infobox holiday
|holiday_name = First Day of Summer
|type =
|image =Sumardagurinn fyrsti.jpg
|imagesize =280px
|caption =First Day of Summer celebrations in Kópavogur
|official_name = sumardagurinn fyrsti
|nickname =
|observedby = Iceland
|litcolor =
|longtype =
|significance =
|begins =
|ends =
|date = first Thursday after 18 April
|celebrations =
|duration = 1 day
|frequency = annual
|observances =
|relatedto =
}}
First Day of Summer ({{lang|is|sumardagurinn fyrsti}} {{IPA|is|ˈsʏːmarˌtaːɣʏrɪn ˈfɪ(r̥)stɪ|}}) is an annual public holiday in Iceland that is celebrated on the first Thursday after 18 April (some time between 19 and 25 April).{{Cite web|url=http://www.visindavefur.is/svar.php?id=65157|title=Hvenær er sumardagurinn fyrsti og er hann vel valinn sem upphaf sumarsins?|website=Vísindavefurinn|language=is|trans-title=When is the First Day of Summer and was it a good choice for the beginning of summer?|access-date=2019-08-25}}
It is a celebration of the start of the first summer month ({{lang|is|Harpa}}) of the old Icelandic calendar. The old calendar had six months of short days (winter) and six months of nightless days (summer), so even though the climate of late April in Iceland is not very summer-like (on fourteen occasions between 1949 and 2015 the average temperature in the capital, Reykjavík, has been below freezing),{{Cite web|url=https://www.vedur.is/vedur/frodleikur/greinar/nr/386|title=Sumardagurinn fyrsti 1949–2015|website=Icelandic Meteorological Office|language=is|access-date=2021-02-06}} the day marks the lengthening of the days and the harsh winter being over.
Parades and organized entertainment are held in various places around Iceland on the first day of summer.{{Cite web|url=https://www.mbl.is/frettir/innlent/2019/04/25/sumardeginum_fyrsta_fagnad/|title=Sumardeginum fyrsta fagnað|date=2019-04-29|website=Morgunblaðið|language=is|access-date=2019-08-26|quote=Festivities will be held in many locations today, the first day of summer. Parades are a part of the program like usually.}}{{Cite web|url=https://reykjavik.is/frettir/sumardagurinn-fyrsti-um-alla-borg|title=Sumardagurinn fyrsti um alla borg|date=2016-04-20|website=Website of the Municipality of Reykjavík|language=is|access-date=2019-08-26}}
According to folk belief, a good summer would be sure to ensue if the temperature dropped below freezing right before the first day of summer. People would place a bowl of water outside for the night and hope that it would freeze.{{cite book|title=Saga daganna|page=50|edition=2|year=1977|author=Árni Björnsson}}