🇮🇸Iceland

Iceland spans 63°23′–66°32′N, a North Atlantic island nation covering roughly 103,000 km² just south of the Arctic Circle. The interior is dominated by a volcanic plateau with active volcanoes including Hekla, Katla, Eyjafjallajökull, Grímsvötn, Bárðarbunga, and the recent Reykjanes peninsula and Fagradalsfjall fissure eruptions, alongside vast ice caps: Vatnajökull at roughly 7,500–7,700 km² is Iceland's largest and one of Europe's largest.

The Highlands plateau rises across the center, while the coastline cuts deep fjords. The highest peak, Hvannadalshnúkur at 2,110 m, crowns Vatnajökull's southern rim. The climate is subpolar oceanic (Köppen Cfc) along the coasts, extraordinarily mild for the latitude thanks to the warm Irminger Current branch of the North Atlantic Drift, with tundra (ET) across much of the highland interior and ice cap conditions (EF) atop major glaciers.

Reykjavík has January highs of about 3°C and lows of −2°C, and July highs of 15°C, with around 800 mm annual rainfall, persistent low cloud, fog, and frequent gales. Akureyri in the more sheltered northeast sees January highs of 3°C and lows near −4°C, and July highs of 15°C, with 570 mm precipitation. Höfn í Hornafirði on the southeast coast beneath Vatnajökull sees January highs of about 3°C and lows near −3°C and July highs of 13°C with 1,450 mm rainfall, while Vík í Mýrdal on the exposed south coast has January highs of about 4°C and lows near −1°C and July highs of 13°C with an exceptional 2,250 mm.

The highland interior is the coldest part of the country, with deep winter snowpack. The all-time temperature range spans approximately −38°C at Grímsstaðir in January 1918 to 30.5°C at Teigarhorn in June 1939. Major natural events include the severe 1973 Eldfell volcanic eruption on Heimaey island, the massive 1996 Skeiðarárjökull jökulhlaup glacial outburst flood, the famous 2010 Eyjafjallajökull eruption that disrupted global aviation, the prolonged 2014–15 Holuhraun lava eruption, the Reykjanes peninsula and Sundhnúksgígar–Grindavík volcanic episodes from 2021 onward, accelerating glacier retreat with Okjökull declared officially dead in 2014, and the rare 2008 Reykjavík summer heatwave.

Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.6°C.