The common perception of Greenland is one of perpetual ice and extreme cold, and while this image holds true for much of the landmass, its climate is far more complex. As the world’s largest island, with over 80% of its surface covered by a massive ice cap, it features stark climatic contrasts. Whether Greenland is always cold depends entirely on location, as coastal regions experience significant seasonal shifts that moderate temperatures considerably.
The Interior Ice Sheet Versus Coastal Regions
Greenland’s climate is sharply divided between the vast interior ice sheet and the narrow, ice-free coastal margins where the population resides. The interior, known as the Inlandsis, is classified as a polar ice cap climate where the monthly mean temperature remains below freezing all year. This dome of ice, which reaches elevations of up to 10,000 feet, creates its own high-altitude, frigid weather system. Even during summer, temperatures on the ice sheet remain well below the freezing point, often failing to rise above 32°F (0°C).
This permanent cold is intensified by the albedo effect, where the bright white snow and ice reflect nearly all incoming solar radiation back into the atmosphere, preventing surface warming. In contrast, coastal areas experience a polar tundra climate, significantly moderated by the surrounding ocean. These ice-free strips frequently see temperatures rise above freezing during the summer, allowing for sparse vegetation. Coastal conditions are highly dependent on proximity to the sea and the influence of ocean currents.
Defining Greenland’s Seasonal Temperature Variance
Coastal settlements, particularly those in the south and west, experience a substantial temperature range between winter and summer. While winter temperatures are consistently below freezing, they are mild for such a high latitude. Average winter temperatures in the capital, Nuuk, are around 16°F (-9°C). Temperatures can plummet significantly, especially in the innermost parts of long fjords which are less influenced by the ocean’s warmth.
The summer months bring a noticeable reprieve, driven by extended hours of sunlight, known as the Midnight Sun in northern regions. During June, July, and August, average temperatures in southern coastal areas range from 40°F to 50°F (4°C to 10°C). In sheltered valleys and the innermost parts of southern fjords, temperatures can occasionally reach or exceed 68°F (20°C). This annual fluctuation prevents permanent freezing along the coasts, allowing for a short period of melting and biological activity.
Key Geographic Factors Shaping the Climate
Greenland’s climate is governed by its high latitude, the presence of the ice sheet, and the movement of oceanic waters. Extending from the North Atlantic into the Arctic Circle, the island’s position dictates that solar radiation is minimal for much of the year, contributing to the overall cold. The elevation of the Inlandsis creates a persistent high-pressure system, which drives cold, dense air outward toward the coasts.
Ocean currents play a powerful role in moderating the climate along the coastlines. The warmer North Atlantic currents (a branch of the Atlantic Meridional Overturning Circulation, or AMOC) flow northwards and temper the winter cold, making Greenland’s winter temperatures milder than those at comparable latitudes in Canada. Conversely, the cold East Greenland Current carries Arctic sea ice and frigid polar water down the eastern coast, contributing to colder, more humid conditions. The interaction of these warm and cold water masses creates the distinct regional climate differences observed between the western and eastern coasts.