Why are Arctic winters milder in coastal maritime regions than in inland continental regions?

Arctic winters are milder in coastal maritime regions than in inland continental regions primarily due to the moderating influence of the ocean.1

In maritime Arctic areas—such as the Aleutian Islands, coastal Greenland, Iceland, and the European Arctic—the proximity to the sea prevents temperatures from dropping to the extreme lows found in the interior. This is further enhanced by the poleward transport of heat through thermohaline circulation, where warm, saline waters from lower latitudes, such as those carried by the North Atlantic Drift, flow into the polar seas and release heat into the atmosphere.12

In contrast, polar continental regions—including parts of Alaska, Canada, and Siberia—experience intensely cold winters because they lack this marine tempering. These inland areas are often dominated by cold air masses, such as the Siberian anticyclone, which contribute to stable, bitterly cold conditions with little snowfall. While coastal areas may experience storminess and higher precipitation, the thermal capacity of the ocean acts as a buffer, keeping mean winter temperatures significantly higher than those in the isolated, frigid continental interiors.13