Iceland
Iceland Geography & Climate
Geography
Iceland is entirely volcanic, built where the Mid-Atlantic Ridge rises above sea level. At Þingvellir the rift is walkable: two rock walls with the plate boundary between them.
Around 11% of the island is under ice. Vatnajökull is the largest glacier in Europe by volume, and it sits over active volcanoes — which is why eruptions here produce jökulhlaup, catastrophic glacial floods.
The interior highlands are a volcanic desert of ash, lava and outwash plains, uninhabited and crossed only by unsurfaced F-roads passable in summer with a high-clearance 4WD.
The habitable land is a coastal ring, which is why the Ring Road exists and why almost every settlement is on it. The Gulf Stream keeps the coast far milder than the latitude implies — Reykjavík is warmer in January than New York.
Built by a rift
Iceland sits astride the Mid-Atlantic Ridge, where the North American and Eurasian plates pull apart, and over a mantle plume that supplies an unusual volume of magma. The island is therefore still being made: it has around thirty active volcanic systems, the plates separate by roughly two centimetres a year, and the rift is visible on the ground at Thingvellir as a valley between two walls of rock.
Ice and fire
Glaciers cover about a tenth of the country, and Vatnajokull is the largest ice cap in Europe by volume. Several volcanoes sit beneath the ice, and an eruption under a glacier produces a jokulhlaup — a sudden meltwater flood capable of moving bridges and rearranging outwash plains, which is why the ring road across the southern sand flats is built to be sacrificed.
An empty interior
The central highlands are a barren plateau of lava, ash and glacier, effectively uninhabited and crossed only by rough tracks open in summer. Almost the entire population lives on a narrow coastal fringe, and two-thirds of it around the capital.
Climate Patterns
Iceland is subarctic but moderated by the Gulf Stream: Reykjavík averages around 1-2°C in January and 11-13°C in July. The cold is not the problem — the wind and the rate of change are.
Weather changes within the hour, and the local saying about waiting five minutes is close to literal. Wind is the defining feature: gusts can exceed 30 m/s, and car doors torn off by wind are a routine and expensive insurance claim.
Daylight is extreme at both ends. Around four to five hours of usable light in late December; near-continuous daylight from late May to July, when it never properly gets dark.
Snow and ice close roads across the country from October to April, sometimes for days at a time.
Milder than the name
Despite sitting on the Arctic Circle, Iceland is warmed by the North Atlantic Drift, and Reykjavik’s winters are milder than those of New York or Moscow. January averages around 0°C in the south-west and July only reaches 11 to 13°C, so the range across the year is small and the summers are cool rather than warm.
Wind and change
The country sits where cold Arctic air meets warmer Atlantic air, which makes it one of the windiest inhabited places in the world and the weather genuinely changeable within hours. Storms can close roads at any season, gusts strong enough to take a car door off are common enough that hire agreements mention them, and the forecast is checked constantly by residents.
Light
The larger seasonal variable. Around the summer solstice it never becomes properly dark; in late December the sun is above the horizon for about four hours in the capital and less in the north. The aurora is visible on clear nights from roughly September to April.