thumb|Satellite photo of Koster Islands. The '''Koster Islands''' (Swedish: ''Kosteröarna'') situated 10 km west of Strömstad, Sweden, comprises an archipelago surrounding the two largest islands, South Koster and North Koster. South Koster has an area of 8 km<sup>2</sup> and North Koster an area of 4 km<sup>2</sup>. The landscape, dominated by smooth bedrock, bears witness to volcanic activity and subsequent wear due to the Ice Age. The rocky coastline is broken by many sandy beaches the largest being ''Kilesand'' on South Koster's east side overlooking the 200 meter deep Koster Fjord. thumb|The narrow sound between North and South Koster.
== Communities ==
South and North Koster are communities with a permanent population of around 340. There is a school, sports hall, shops, church, and galleries where handcrafts and arts are exhibited. Both farming and fishing are important, and during the 1600s Koster exported lobster to Holland. There are several small harbors, popular with sailors from both near and far. Rooms can be rented from the Ekenäs Hotel or from private homes or cabins. There is also a campsite on North Koster.
An electrically-driven ferry operates constantly between the two islands, a distance of 58 meters. As one moves inland, farmland, woods and rich vegetation becomes apparent and there are many trails. South Koster has a network of roads and paths, which can be explored by bicycle or in small golf buggies, both of which can be rented. On North Koster, it is also possible to rent small boats. Restrictions regarding the right of access, ''Allemansrätten'', forbid open fires, and camping is only allowed at the designated campsite. Private cars are not permitted.
== Climate == The Koster Islands have a marine west coast climate that has a narrower range of temperatures than inland and areas on the east coast on similar parallels. The islands have a small diurnal temperature variation resulting in mild night time temperatures with frosts being less common than expected for areas on similar parallels both in Sweden and globally. Still yet, sleet was recorded on Nordkoster as late as June 12, 1981, at a temperature of only +2.7 °C.
{{Weather box |location = Nordkoster |metric first = Yes |single line = Yes |Jan record high C = 10.1 |Feb record high C = 8.9 |Mar record high C = 15.5 |Apr record high C = 24.0 |May record high C = 29.7 |Jun record high C = 29.9 |Jul record high C = 30.3 |Aug record high C = 30.5 |Sep record high C = 25.5 |Oct record high C = 18.6 |Nov record high C = 14.1 |Dec record high C = 10.8 |year record high C = 30.5 |Jan high C = 2.1 |Feb high C = 1.5 |Mar high C = 4.5 |Apr high C = 9.6 |May high C = 14.3 |Jun high C = 17.9 |Jul high C = 20.5 |Aug high C = 20.2 |Sep high C = 16.3 |Oct high C = 10.8 |Nov high C = 7.0 |Dec high C = 3.7 |year high C = 10.7 |Jan mean C = 0.2 |Feb mean C = -0.2 |Mar mean C = 2.2 |Apr mean C = 6.8 |May mean C = 11.4 |Jun mean C = 16.1 |Jul mean C = 17.9 |Aug mean C = 17.5 |Sep mean C = 13.9 |Oct mean C = 8.8 |Nov mean C = 5.3 |Dec mean C = 1.8 |year mean C = 8.4 |Jan low C = -1.6 |Feb low C = -2.0 |Mar low C = 0.0 |Apr low C = 4.0 |May low C = 8.5 |Jun low C = 12.3 |Jul low C = 15.2 |Aug low C = 14.9 |Sep low C = 11.6 |Oct low C = 6.9 |Nov low C = 3.6 |Dec low C = 0.0 |year low C = 6.1 |Jan record low C = -22.3 |Feb record low C = -20.5 |Mar record low C = -15.2 |Apr record low C = -5.3 |May record low C = -1.7 |Jun record low C = 2.7 |Jul record low C = 5.6 |Aug record low C = 7.0 |Sep record low C = 1.2 |Oct record low C = -6.1 |Nov record low C = -10.2 |Dec record low C = -17.9 |year record low C = -22.3 |Jan precipitation mm = 48 |Feb precipitation mm = 42 |Mar precipitation mm = 40 |Apr precipitation mm = 40 |May precipitation mm = 43 |Jun precipitation mm = 49 |Jul precipitation mm = 46 |Aug precipitation mm = 65 |Sep precipitation mm = 68 |Oct precipitation mm = 80 |Nov precipitation mm = 69 |Dec precipitation mm = 47 |year precipitation mm = 627 |source 1 = SMHI Precipitation Normals<ref>{{cite web | url =http://data.smhi.se/met/climate/time_series/month_year/normal_1961_1990/SMHI_month_year_normal_61_90_precipitation_mm.txt | title =Precipitation Normals 1961-1990 (Swedish) | publisher =Swedish Metereological and Hydrological Institute (Nordkoster code 8154) | language = | access-date =2015-05-11 | archive-url =https://web.archive.org/web/20180928213811/http://data.smhi.se/met/climate/time_series/month_year/normal_1961_1990/SMHI_month_year_normal_61_90_precipitation_mm.txt | archive-date =2018-09-28 | url-status =dead }}</ref> |source 2 = SMHI Monthly Data 2002-2015<ref name=eather2>{{cite web | url=http://www.smhi.se/klimatdata/meteorologi/temperatur/2.1240 | title=Monthly and Yearly Statistics (Swedish) | publisher=SMHI | accessdate=2 April 2016 | archive-date=2 May 2019 | archive-url=https://web.archive.org/web/20190502092934/http://www.smhi.se/klimatdata/meteorologi/temperatur/2.1240 | url-status=dead }}</ref> }}
== Tourism on the islands ==
Koster is a well-established and popular tourist destination, attracting as many as 90,000 tourists<ref>{{cite web|title=Kosterhavets National Park|url=http://www3.lansstyrelsen.se/_vastragotaland/Projektwebbar/Kosterhavet/English/|accessdate=10 May 2011|archive-url=https://web.archive.org/web/20110622113541/http://www3.lansstyrelsen.se/_vastragotaland/Projektwebbar/Kosterhavet/English/|archive-date=22 June 2011|url-status=dead}}</ref> each year, renowned for being one of Sweden's sunniest places offering bathing opportunities. During the summer there are a variety of events and activities, such as a music festival, mackerel race, and trips to the seal colonies. Several pubs and restaurants offer a varied menu, often based on seafood from local fishermen, such as shrimp, oyster, crayfish, crab, and lobster.
Connections to the mainland are good with sixteen ferry departures daily from Strömstad, a crossing of around 45 minutes. Private cars can be parked at the car park just outside the center of Strömstad from where buses run free of charge to the harbor square.
== Gallery == <gallery mode="packed" heights="120" perrow=4> File:Strömstad August 2012 - panoramio.jpg|Strömstad on the mainland, August 2012 File:Koster 7755C (1874187710).jpg|Koster fisherman File:Koster 9497 (7768461348).jpg|Boathouses File:Koster 9502 (7768457808).jpg|Boathouses File:Koster 9461 (7768480214).jpg|Björnsängen, northernmost beach File:Koster 9631 (7768314194).jpg|Popular type of motorsailer File:Koster 9720 (7768266558).jpg|Typical motorboat File:Koster 9684 (7768284938).jpg|Koster inland terrain File:Koster 9533 (7768346000).jpg|Koster shore terrain </gallery>
== References == {{reflist}}
== Additional sources == * Kosterbladet 2010
== External links == * [http://www.kosteroarna.com/eng.htm Koster: Islands in the Skagerrak] {{Webarchive|url=https://web.archive.org/web/20120626004357/http://www.kosteroarna.com/eng.htm |date=2012-06-26 }} * [http://www.kosterturist.se/vandringsleder.pdf Map of Koster Islands] {{Webarchive|url=https://web.archive.org/web/20160304065158/http://www.kosterturist.se/vandringsleder.pdf |date=2016-03-04 }}
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Category:Archipelagoes of Sweden Category:Islands on the Swedish West Coast Category:Landforms of Västra Götaland County Category:Islands of Västra Götaland County Category:Strömstad Municipality Category:Car-free islands of Europe