The belief that Iceland is a tundra is common, fueled by the island’s treeless, stark, and desolate appearance. However, the official climate classification for most of the country is more temperate than a true tundra. Iceland’s climate is highly nuanced, existing where warm ocean currents clash with Arctic air masses. Understanding the reality requires examining the scientific definition of a tundra and how Iceland’s unique geography alters its climate.
Defining Tundra: Climate and Characteristics
A tundra environment is defined by specific temperature and ground conditions that severely limit plant life. The primary criterion for a tundra climate is that the average temperature of the warmest month must remain below 10°C (50°F). This threshold prevents the growth of tall, upright trees, resulting in a characteristic treeless landscape.
Another defining feature of the Arctic tundra is permafrost, which is ground that remains permanently frozen for at least two consecutive years. This frozen layer prevents water drainage and confines plant roots to a shallow, seasonally thawed active layer. Consequently, vegetation is restricted to low-growing forms, such as mosses, lichens, sedges, and dwarf shrubs.
Iceland’s Official Climate Classification
Most of Iceland’s inhabited areas, particularly the low-lying coastal regions, do not meet the temperature criteria for tundra. Under the Köppen-Geiger system, the majority of the coastal perimeter is classified as a Subpolar Oceanic Climate. This classification reflects that coastal areas experience relatively mild winters and summer temperatures that frequently exceed the 10°C threshold.
The average July temperature in the southern part of the island often ranges between 10°C and 13°C. This data disqualifies the region from being classified as a true tundra, as no month can average above 10°C. Winter temperatures along the southern coast average around 1°C, rarely dipping below freezing for extended periods. This maritime influence results in a climate far milder than that of landmasses at a similar latitude, such as Greenland or Northern Canada.
Geographical Factors That Prevent Widespread Tundra
Iceland avoids the deep, sustained freeze required for widespread tundra due to its location relative to major ocean currents. The island sits directly in the path of the North Atlantic Current, an extension of the Gulf Stream. This current transports warm, tropical water northeastward, moderating the country’s climate year-round. This insulating effect prevents coastal waters from freezing and keeps temperatures significantly higher than expected for its latitude.
Iceland’s geological setting also prevents the formation of deep, continuous permafrost. The island is highly volcanically active, sitting atop the Mid-Atlantic Ridge. The extensive geothermal heat that powers hot springs and geysers contributes to warmer ground temperatures. This internal heat source, combined with the oceanic influence, prevents the conditions necessary for permafrost formation in the lowlands.
The Tundra-Like Regions of Iceland
While the coast is Subpolar Oceanic, a significant portion of the interior qualifies as a true tundra climate. The remote, high-elevation areas, known as the Central Highlands, are classified as Tundra. These regions are shielded from the ocean’s moderating effects and experience substantially colder conditions.
In the Highlands, the average summer temperatures remain low enough to meet the tundra criteria. The vegetation is sparse, consisting primarily of low-growing forms typical of tundra, such as mosses, lichens, and dwarf birch. Permafrost is present in these colder zones, but it is typically discontinuous, existing in patches rather than as a solid layer. This regional variation contributes to the popular, but inaccurate, perception that the entire country is frozen year-round.