The subarctic is a climate zone and geographic region stretching roughly from 50° to 70° north latitude, sitting between the temperate forests to the south and the frozen Arctic tundra to the north. It spans massive portions of North America (from Alaska to Newfoundland) and Eurasia (from northern Scandinavia to Siberia), making it one of the largest climate zones on Earth. If you picture the vast, cold forests of Canada or Russia, you’re picturing the subarctic.
Where the Subarctic Sits
The subarctic doesn’t have sharp borders drawn on a map. Instead, its boundaries are defined by temperature. The southern edge begins where winters become consistently harsh and summers stay cool, around 50°N in North America. The northern edge, between 60° and 70°N depending on the continent, is where trees can no longer grow and tundra takes over. This tree line is one of the most visible ecological boundaries on the planet.
In practical terms, the subarctic covers interior Alaska, most of Canada’s provinces and territories, Iceland, northern Scandinavia (Finland, Sweden, Norway), and a huge belt of Russia stretching from west of the Urals all the way to the Pacific coast. Cities like Fairbanks, Alaska and Murmansk, Russia sit squarely in this zone. Anchorage, Alaska’s largest city, serves as a major trade and service hub on the subarctic’s edge.
What the Climate Feels Like
The defining feature of the subarctic climate is extreme seasonality. Winters are long, dark, and brutally cold. Summers are short but surprisingly warm in some interior areas, with temperatures occasionally reaching 25°C (77°F). On average, though, summer temperatures rarely exceed 16°C (61°F). Only one to three months of the year have average temperatures above 10°C (50°F), which is the rough threshold for tree growth.
Winter cold varies dramatically. In the standard subarctic climate, the coldest month averages below 0°C (32°F). But in the most extreme pockets, particularly in eastern Siberia, the coldest month can average below -38°C (-36°F). These are among the coldest inhabited places on Earth. Some subarctic areas receive relatively even precipitation year-round, while others, particularly in eastern Asia, get the vast majority of their rain and snow during summer months in a monsoon-like pattern.
Daylight swings are dramatic. At the higher latitudes of the subarctic, near or above 66°N, summer brings the midnight sun, with weeks of nearly continuous daylight. Winter reverses this completely, plunging the same areas into polar night, where the sun doesn’t rise at all. Even at the lower end of the subarctic, around 55°N, winter days may last only six or seven hours while summer days stretch past 18.
Boreal Forest: The Subarctic Landscape
The subarctic’s signature ecosystem is the boreal forest, also called taiga. It’s the largest land biome on Earth, a seemingly endless expanse of coniferous trees. Spruce, fir, and larch dominate, along with deciduous species like birch and aspen. These trees are short by temperate forest standards, rarely exceeding 15 meters (about 50 feet). In the harshest subarctic conditions, they may grow only 2 meters tall, stunted by cold, wind, and thin soil.
The forest floor is blanketed with mosses and lichens rather than the leafy undergrowth found in warmer forests. As you move north, the dense forest gradually thins into lichen woodlands, where trees are widely spaced and ground cover dominates. At the very northern edge, isolated patches of forest-tundra mark the transition to treeless Arctic landscapes. This gradient from closed forest to scattered trees to open tundra plays out over hundreds of kilometers.
Beneath the forest, the ground itself is often permanently frozen. Permafrost, soil that stays below 0°C year-round, is widespread across the subarctic, particularly in its northern reaches. In some areas the permafrost is continuous, while further south it becomes patchy or discontinuous, thawing in spots where conditions allow. This frozen ground shapes everything from drainage patterns to what can be built on the surface.
How Subarctic Animals Survive
The subarctic is home to caribou, moose, wolves, wolverines, bears, and smaller mammals like lemmings, voles, and snowshoe hares. Birds migrate in enormous numbers during summer to breed, then leave before winter. The animals that stay year-round have evolved remarkable strategies for surviving extreme cold.
Mammals adapt to subarctic cold in two stages. When temperatures first drop sharply, animals generate heat through shivering. As cold exposure continues over days and weeks, their bodies shift to a more efficient form of heat production that doesn’t require muscle contractions. This allows them to maintain a high metabolic rate without the energy cost of constant shivering. Lemmings, among the most cold-adapted rodents on Earth, complete this transition within roughly a week, far faster than mammals from temperate regions.
Wolverines show another interesting adaptation: their resting body temperature cycles between a higher and lower setting roughly every 12 hours, conserving energy during inactive periods and ramping up heat production when active. Many subarctic mammals also grow dramatically thicker winter fur, increase their food intake as winter approaches, and either hibernate (bears) or remain active under insulating snow cover (lemmings and voles, which build tunnel networks beneath the snowpack).
People and Economies of the Subarctic
Despite its harsh climate, the subarctic has been home to Indigenous peoples for thousands of years, from the Athabascan peoples of interior Alaska and Canada to the Sámi of northern Scandinavia and numerous groups across Siberia. Modern settlement is sparse but not insignificant. Fairbanks and Anchorage in Alaska, Murmansk and Yakutsk in Russia, and Rovaniemi in Finland are among the notable population centers.
The subarctic economy revolves around natural resources. Oil and gas extraction is a major employer, particularly on Alaska’s North Slope, where petroleum development drives the regional economy even though most workers commute from elsewhere. Mining is significant across the zone: zinc mining near Kotzebue, Alaska, gold mining outside Fairbanks, and silver mining near Juneau represent just a slice of the mineral extraction taking place across subarctic North America and Eurasia. Logging has historically been important, especially in Alaska’s Tongass National Forest, where long-term federal contracts supplied pulp mills and sawmills for decades. Commercial fishing anchors coastal communities, with major concentrations in towns like Kodiak, Dutch Harbor, and Sitka.
Tourism has become one of the fastest-growing industries in parts of the subarctic, driven by cruise ships, independent travelers, and a growing eco-tourism sector. The appeal is straightforward: vast wilderness, northern lights, midnight sun, and wildlife that can’t be seen anywhere else.
A Region Changing Fast
The subarctic is warming faster than the global average, a pattern that has held for decades. This accelerated warming is pushing the tree line northward as conditions become suitable for forest growth in areas that were previously too cold. Between 2000 and 2019, satellite data showed that the forest line in North America shifted north roughly in step with rising temperatures. In Eurasia, the forest line lagged well behind the warming, likely because factors like water stress, winter extremes, and thawing permafrost complicate tree establishment even when summers warm.
This northward creep of forests matters because it transforms the landscape in ways that ripple through ecosystems. Darker forest absorbs more solar energy than reflective tundra, potentially accelerating local warming further. Thawing permafrost releases stored carbon. Animal species adapted to open tundra lose habitat while forest-dwelling species expand their range. The subarctic, already defined by extremes, is becoming a region where the pace of change is itself extreme.