The subarctic climate is a climate characterised by long, usually very cold
winters, and short, cool to mild summers. It is found on large
landmasses, away from the moderating effects of an ocean, generally at
latitudes from 50° to 70°N poleward of the humid continental climates. These
climates represent Köppen climate classification Dfc, Dwc, Dfd, and Dwd.
In very small areas at high altitudes around the Mediterranean Basin, Iran,
Tajikistan, Turkey, northwestern United States the climate is classified as Dsc
with a dry summer climate, such as in Seneca, Oregon.
Description This type of climate offers some of the
most extreme seasonal temperature variations found on the planet: in
winter, temperatures can drop to −40 °C and in summer, the temperature may
exceed 30 °C. However, the summers are short; no more than three months of the
year must have a 24-hour average temperature of at least 10 °C to fall
into this category of climate. With 5–7 consecutive months where the
average temperature is below freezing, all moisture in the soil and subsoil
freezes solidly to depths of many feet. Summer warmth is insufficient to thaw
more than a few surface feet, so permafrost prevails under most areas not
near the southern boundary of this climate zone. Seasonal thaw penetrates
from 2 to 14 ft, depending on latitude, aspect, and type of ground. Some
northern areas with subarctic climates located near oceans, have milder winters
and no permafrost, and are more suited for farming unless precipitation is
excessive. The frost-free season is very short, varying from about 45 to 100 days
at most, and a freeze can occur during any month in many areas.
= Precipitation= Most subarctic climates have very little
precipitation, typically no more than 15 inches over an entire year. Away from
the coasts, precipitation occurs mostly in the warmer months, while in coastal
areas with subarctic climates the heaviest precipitation is usually during
the autumn months when the relative warmth of sea vis-à-vis land is
greatest. Low precipitation, by the standards of more temperate regions with
longer summers and warmer winters, is typically sufficient in view of the very
low evapotranspiration to allow a water-logged terrain in many areas of
subarctic climate and to permit snow cover during winter.
A notable exception to this pattern is that subarctic climates occurring at
high altitudes in otherwise temperate regions have extremely high
precipitation due to orographic lift. Mount Washington, with temperatures
typical of a subarctic climate, receives an average rain-equivalent of 101.91
inches of precipitation per year. Coastal areas of Khabarovsk Krai also
have much higher precipitation in summer due to orographic influences in July in
some areas), whilst the mountainous Kamchatka peninsula and Sakhalin island
are even wetter since orographic moisture is not confined to the warmer
months and creates large glaciers in Kamchatka. Labrador, in eastern Canada,
is similarly wet throughout the year due to the semi-permanent Icelandic Low and
can receive up to 1,300 millimetres of rainfall equivalent per year, creating a
snow cover of up to 1.5 metres that does not melt until June.
= Vegetation and land use= Vegetation in regions with subarctic
climates is generally of low diversity, as only hardy species can survive the
long winters and make use of the short summers. Trees are mostly limited to
conifers, as few broadleaved trees are able to survive the very low
temperatures in winter. This type of forest is also known as taiga, a term
which is sometimes applied to the climate found therein as well. Even
though the diversity may be low, numbers are high, and the taiga forest is the
largest forest biome on the planet, with most of the forests located in Russia
and Canada. The process by which plants become acclimated to cold temperatures
is called hardening. Agricultural potential is generally
poor, due to the natural infertility of soils and the prevalence of swamps and
lakes left by departing ice sheets, and short growing seasons prohibit all but
the hardiest of crops. In some areas, ice has scoured rock surfaces bare,
entirely stripping off the overburden. Elsewhere rock basins have been formed
and stream courses dammed, creating countless lakes.
Distribution The Dfc climate, by far the most common
subarctic type, is found in the following areas:
Much of Siberia The Kamchatka Peninsula
Parts of Scotland The northern and central parts of the
Kuril Islands and Sakhalin Island The Western Alps between 1,600 and 2,100
meters, and the Eastern Alps between 1,450 and 1,800 meters –France,
Switzerland, Germany, Italy and Austria. The center of Romania.
The Tatra Mountains in Poland, above 800m.
The Eastern Anatolia, between 1,600 and 2,100 meters – Turkey.
The Pyrenees, between 1,600 and 2,100 meters – Andorra, France and Spain.
The northern half of Scandinavia Most of Interior, Western and
Southcentral Alaska The high Rocky Mountains in Colorado,
Wyoming, Idaho and Montana and the White Mountains of New Hampshire
Much of Canada from about 53–55°N to the tree line, including:
Southern Labrador Certain areas within Newfoundland
interior and along its northern coast Quebec: Jamésie, Côte-Nord and far
southern Nunavik Far northern Ontario
The northern Prairie Provinces Most of the Yukon
Most of the Northwest Territories In parts of Asia, the Siberian High
makes the winters so dry of rainfall equivalent per month) that snow cover is
very limited, creating a Dwc climate in: Much of northern Mongolia
Russia: Most of Khabarovsk Krai except the south
Southeastern Sakha Republic Southern Magadan Oblast
Northern Amur Oblast Northern Buryatia
Zabaykalsky Krai Irkutsk Oblast
China: Tahe County and Mohe County in
Heilongjiang Northern Hulunbuir in Inner Mongolia
Gannan in Gansu Huangnan, eastern Hainan and eastern
Guoluo in Qinghai Most of Garzê and Ngawa Autonomous
Prefectures in Sichuan Most of Qamdo Prefecture in the Tibet
Autonomous Region Parts of Ladakh and Spiti regions of
India. Further north in Siberia, continentality
increases so much that winters can be exceptionally severe, averaging below
−38 °C, even though the hottest month still averages more than 10 °C. This
creates Dfd and Dwd climates. The Southern Hemisphere, which has no
large landmasses in the upper-middle latitudes that can have both the short
but well-defined summers and severe winters that characterize this climate,
has very few locations with this climate. One example is parts of the
Snowy Mountains in Australia. Should one go poleward or even toward a
polar sea, one finds that the warmest month has an average temperature of less
than 10 °C, and the subarctic climate grades into a tundra climate even less
suitable for trees. Equatorward or toward a lower altitude, this climate
grades into the humid continental climates with longer summers; in a few
locations close to a temperate sea, this climate can grade into a short-summer
version of an oceanic climate, the subpolar oceanic climate, as the sea is
approached. In China and Mongolia, as one moves southwestwards or towards
lower altitudes, temperatures increase but precipitation is so low that the
subarctic climate grades into a cold semi-arid climate.
Charts of selected sites See also
Boreal ecology Boreal forest
Plants of continental subarctic climate Köppen climate classification
Subantarctic References