Subarctic climate

The subarctic climate (also called subpolar climate, or boreal 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. Subarctic or boreal climates are the source regions for the cold air that affects temperate latitudes to the south in winter. These climates represent Köppen climate classification Dfc, Dwc, Dsc, Dfd, Dwd and Dsd.

Subarctic climate worldwide

Dsc   Dsd

Dwc   Dwd

Dfc   Dfd

Description

This type of climate offers some of the most extreme seasonal temperature variations found on the planet: in winter, temperatures can drop to below −50 °C (−58 °F) and in summer, the temperature may exceed 26 °C (79 °F). However, the summers are short; no more than three months of the year (but at least one month) must have a 24-hour average temperature of at least 10 °C (50 °F) to fall into this category of climate and the coldest month should average below 0 °C (32 °F) (or −3 °C (27 °F)). Record low temperatures can approach −70 °C (−94 °F).[1]

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 (0.61 to 4.27 m), depending on latitude, aspect, and type of ground.[2] Some northern areas with subarctic climates located near oceans (southern Alaska, the northern fringe of Europe, Sakhalin Oblast and Kamchatka Oblast), 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.

Description

The first D indicates continental.

• s: A dry summer—the driest month in the high-sun half of the year (April to September in the Northern Hemisphere, October to March in the Southern Hemisphere) has less than 30 millimetres (1.18 in)/40 millimetres (1.57 in) of rainfall and has exactly or less than ​¹⁄₃ the precipitation of the wettest month in the low-sun half of the year (October to March in the Northern Hemisphere, April to September in the Southern Hemisphere),
• w: A dry winter—the driest month in the low-sun half of the year has exactly or less than one‑tenth of the precipitation found in the wettest month in the summer half of the year,
• f: Without dry season—does not meet either of the alternative specifications.

The third letter denotes temperature:

• c: Regular subarctic, only 1–3 months above 10 °C (50.0 °F), coldest month below −3 °C (26.6 °F).
• d: Extreme subarctic, only 1–3 months above 10 °C (50.0 °F), coldest month at or below −38 °C (−36.4 °F).

Precipitation

Most subarctic climates have little precipitation, typically no more than 380 mm (15 in) 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 (2,588.5 mm) of precipitation per year.[3] Coastal areas of Khabarovsk Krai also have much higher precipitation in summer due to orographic influences (up to 175 millimetres (6.9 in) in July in some areas), whilst the mountainous Kamchatka peninsula and Sakhalin island are even wetter, since orographic moisture isn't 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 (51 in) of rainfall equivalent per year, creating a snow cover of up to 1.5 metres (59 in) 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 (boreal) 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[4] and the prevalence of swamps and lakes left by departing ice sheets, and short growing seasons prohibit all but the hardiest of crops. Despite the short season, the long summer days at such latitudes do permit some agriculture. 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.[2]

Distribution

Dfc distribution

The Dfc climate, by far the most common subarctic type, is found in the following areas:[5][6]

View of pines in the Kuysumy mountains in Siberia

• Northern Eurasia
  • The majority of Siberia
  • The Kamchatka Peninsula and the northern and central parts of the Kuril Islands and Sakhalin Island
  • The northern inland regions of Fennoscandia (milder winters in coastal areas), including most of Finland and the Hardangervidda plateau
  • The Western Alps between 1,600 and 2,100 meters (5,200 and 6,900 ft), and the Eastern Alps between 1,450 and 1,800 meters (4,760 and 5,910 ft)
  • Central Romania
  • Some parts of central Germany
  • The Tatra Mountains in Poland and Slovakia, above 800 meters (2,600 ft).
  • The Pyrenees, between 1,600 and 2,100 meters (5,200 and 6,900 ft)
  • The Eastern Anatolia, between 1,600 and 2,100 meters (5,200 and 6,900 ft)
  • Mountain summits in Scotland, most notably in the Cairngorms and the Nevis Range

Subarctic climate in Alaska, near Yukon

• North America
  • Most of Interior, Western and Southcentral Alaska
  • The high Rocky Mountains in Colorado, Wyoming, Idaho, Utah, 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
    • The Rocky Mountain Foothills in Alberta and British Columbia
    • Most of the Yukon
    • Most of the Northwest Territories

Dsc and Dsd distribution

Climates classified as Dsc or Dsd, with a dry summer, are rare, occurring in very small areas at high altitudes around the Mediterranean Basin, Iran, Kyrgyzstan, Tajikistan, Turkey, Alaska and other parts of the northwestern United States (Eastern Washington, Eastern Oregon, Southern Idaho, California's Eastern Sierra) and the Russian Far East, such as in Seneca, Oregon or Atlin, British Columbia.

Dwc distribution

In parts of East Asia, like China, the Siberian High makes the winters colder than places like Scandinavia or Alaska interior but extremely dry (typically with around 5 millimeters (0.20 in) 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 (due to extreme altitude)
  • Huangnan, eastern Hainan and eastern Guoluo in Qinghai (due to extreme altitude)
  • Most of Garzê and Ngawa Autonomous Prefectures (due to extreme altitude) in Sichuan
  • Most of Qamdo Prefecture (due to extreme altitude) in the Tibet Autonomous Region
• Parts of Ladakh (including Siachen Glacier) and Spiti regions of India
• Parts of Kaema Plateau (including Mount Baekdu, Samjiyon, Musan) in North Korea

Further north in Siberia, continentality increases so much that winters can be exceptionally severe, averaging below −38 °C (−36 °F), even though the hottest month still averages more than 10 °C (50 °F). This creates Dfd, Dwd and Dsd climates.

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 (50 °F), 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 (and usually less-severe winters); in a few locations close to a temperate sea (as in North Norway and southern Alaska), 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

Anchorage, Alaska, United States
Climate chart (explanation)
J F M A M J J A S O N D     19     −5 −12     19     −3 −10     15     1 −7     12     7 −2     19     14 4     24     18 9     46     19 11     82     18 10     76     13 5     52     5 −2     30     −2 −9     28     −4 −10 Average max. and min. temperatures in °C Precipitation totals in mm Source: NOAA
Imperial conversion J F M A M J J A S O N D     0.7     23 11     0.7     27 14     0.6     35 19     0.5     45 29     0.7     57 39     0.9     64 47     1.8     66 52     3.2     64 50     3     55 42     2     41 29     1.2     28 17     1.1     24 13 Average max. and min. temperatures in °F Precipitation totals in inches

Yellowknife, Northwest Territories, Canada
Climate chart (explanation)
J F M A M J J A S O N D     14     −23 −31     13     −19 −28     13     −11 −23     11     0 −11     19     11 1     27     18 9     35     21 12     41     18 10     33     10 4     35     1 −4     24     −10 −18     16     −20 −28 Average max. and min. temperatures in °C Precipitation totals in mm Source: Environment Canada[7]
Imperial conversion J F M A M J J A S O N D     0.6     −9 −24     0.5     −1 −19     0.5     12 −10     0.4     33 12     0.8     51 33     1.1     65 48     1.4     70 54     1.6     65 51     1.3     51 39     1.4     34 24     0.9     14 0     0.6     −3 −18 Average max. and min. temperatures in °F Precipitation totals in inches

Moosonee, Ontario, Canada
Climate chart (explanation)
J F M A M J J A S O N D     34     −15 −27     23     −12 −26     32     −5 −20     39     4 −9     54     12 −1     71     18 5     101     22 8     76     20 8     90     15 4     73     8 −1     54     −1 −9     35     −11 −22 Average max. and min. temperatures in °C Precipitation totals in mm Source: Environment Canada[8]
Imperial conversion J F M A M J J A S O N D     1.3     5 −16     0.9     11 −15     1.2     24 −4     1.5     38 16     2.1     53 31     2.8     65 40     4     71 47     3     69 46     3.5     58 39     2.9     46 31     2.1     31 16     1.4     12 −8 Average max. and min. temperatures in °F Precipitation totals in inches

Samedan, Graubünden, Switzerland
Climate chart (explanation)
J F M A M J J A S O N D     30     −2 −18     25     0 −17     31     3 −12     44     6 −6     81     12 −1     87     16 2     89     18 3     99     18 3     72     15 0     59     11 −4     54     4 −11     31     −2 −16 Average max. and min. temperatures in °C Precipitation totals in mm Source: MeteoSchweiz[9]
Imperial conversion J F M A M J J A S O N D     1.2     28 0     1     32 1     1.2     37 11     1.7     44 22     3.2     53 30     3.4     60 35     3.5     65 37     3.9     64 37     2.8     59 32     2.3     51 24     2.1     38 13     1.2     29 3 Average max. and min. temperatures in °F Precipitation totals in inches

Luleå, Sweden
Climate chart (explanation)
J F M A M J J A S O N D     32     −7 −13     26     −6 −13     23     −1 −9     18     4 −3     23     11 2     32     17 9     42     20 12     42     18 11     31     12 6     34     6 0     31     −2 −6     27     −6 −11 Average max. and min. temperatures in °C Precipitation totals in mm Source: World Weather Information[10]
Imperial conversion J F M A M J J A S O N D     1.3     19 9     1     21 9     0.9     30 16     0.7     39 27     0.9     52 36     1.3     63 48     1.7     68 54     1.7     64 52     1.2     54 43     1.3     43 32     1.2     28 21     1.1     21 12 Average max. and min. temperatures in °F Precipitation totals in inches

Nerdal/Mo i Rana, Norway
Climate chart (explanation)
J F M A M J J A S O N D     146     −3 −8     117     −2 −7     112     2 −4     74     5 −1     64     12 4     70     16 8     97     18 10     110     16 9     155     11 6     186     6 2     136     1 −4     163     −1 −6 Average max. and min. temperatures in °C Precipitation totals in mm Source: met.no/klimastatistikk/eklima
Imperial conversion J F M A M J J A S O N D     5.7     27 17     4.6     29 19     4.4     35 24     2.9     42 30     2.5     53 38     2.8     61 46     3.8     64 51     4.3     62 49     6.1     52 42     7.3     43 35     5.4     34 26     6.4     30 20 Average max. and min. temperatures in °F Precipitation totals in inches

Tromsø, Norway
Climate chart (explanation)
J F M A M J J A S O N D     95     −2 −7     87     −2 −7     72     0 −5     64     3 −2     48     8 2     59     13 6     77     15 9     82     14 8     102     9 4     131     5 1     108     1 −3     106     −1 −5 Average max. and min. temperatures in °C Precipitation totals in mm Source: World Weather Information Service
Imperial conversion J F M A M J J A S O N D     3.7     28 20     3.4     28 20     2.8     31 23     2.5     37 28     1.9     46 36     2.3     55 43     3     60 48     3.2     57 46     4     49 40     5.2     40 33     4.3     33 27     4.2     30 22 Average max. and min. temperatures in °F Precipitation totals in inches

Kiruna, Sweden
Climate chart (explanation)
J F M A M J J A S O N D     30     −11 −22     25     −9 −20     26     −5 −18     27     −1 −9     34     8 −2     49     15 5     86     18 7     74     15 5     49     10 1     47     −2 −11     42     −7 −13     34     −9 −20 Average max. and min. temperatures in °C Precipitation totals in mm Source: SMHI[11]
Imperial conversion J F M A M J J A S O N D     1.2     12 −7     1     16 −4     1     23 −1     1.1     30 15     1.3     47 29     1.9     59 41     3.4     64 45     2.9     59 42     1.9     49 33     1.9     28 13     1.7     20 8     1.3     16 −4 Average max. and min. temperatures in °F Precipitation totals in inches

Verkhoyansk, Sakha Republic, Russia
Climate chart (explanation)
J F M A M J J A S O N D     6     −43 −49     6     −37 −46     5     −20 −39     6     −3 −22     12     10 −3     23     20 6     33     23 9     32     18 4     14     9 −3     13     −9 −19     10     −32 −40     8     −40 −47 Average max. and min. temperatures in °C Precipitation totals in mm Source: Pogoda.ru.net
Imperial conversion J F M A M J J A S O N D     0.2     −45 −56     0.2     −34 −51     0.2     −4 −37     0.2     26 −8     0.5     50 27     0.9     68 43     1.3     74 48     1.3     65 40     0.6     47 27     0.5     16 −3     0.4     −26 −40     0.3     −40 −52 Average max. and min. temperatures in °F Precipitation totals in inches

Mohe, Heilongjiang, China
Climate chart (explanation)
J F M A M J J A S O N D     5     −22 −36     4.4     −13 −33     6.9     −3 −24     24     8 −8     33     18 0     68     24 8     99     26 12     107     23 9     50     16 1     16     5 −10     13     −11 −25     7.4     −21 −34 Average max. and min. temperatures in °C Precipitation totals in mm Source: Weather China[12]
Imperial conversion J F M A M J J A S O N D     0.2     −7 −33     0.2     9 −28     0.3     26 −12     0.9     46 19     1.3     64 33     2.7     76 46     3.9     78 53     4.2     74 49     2     62 35     0.6     41 14     0.5     13 −14     0.3     −6 −29 Average max. and min. temperatures in °F Precipitation totals in inches

Lukla, Nepal
Climate chart (explanation)
J F M A M J J A S O N D     11     1 −18     18     2 −16     22     5 −12     28     8 −7     34     12 −3     96     15 2     154     14 4     145     13 4     81     13 1     37     9 −7     6.2     6 −13     13     3 −16 Average max. and min. temperatures in °C Precipitation totals in mm Source: weatherbase.com[13]
Imperial conversion J F M A M J J A S O N D     0.4     34 −1     0.7     35 3     0.9     40 10     1.1     47 19     1.4     53 26     3.8     58 35     6.1     58 39     5.7     56 38     3.2     55 33     1.5     48 20     0.2     42 10     0.5     38 3 Average max. and min. temperatures in °F Precipitation totals in inches

Crater Lake, Oregon, United States
Climate chart (explanation)
J F M A M J J A S O N D     267     1 −8     205     2 −8     196     3 −7     123     6 −5     84     10 −2     57     15 2     20     21 5     25     21 5     52     17 3     127     11 −1     239     4 −5     290     2 −7 Average max. and min. temperatures in °C Precipitation totals in mm Source: SHMI[14]
Imperial conversion J F M A M J J A S O N D     11     34 18     8.1     35 18     7.7     37 19     4.8     43 23     3.3     50 29     2.2     58 35     0.8     69 41     1     69 41     2     63 37     5     52 31     9.4     40 24     11     35 20 Average max. and min. temperatures in °F Precipitation totals in inches

Norilsk, Krasnoyarsk Krai, Russia
Climate chart (explanation)
J F M A M J J A S O N D     22     −25 −34     17     −24 −33     20     −17 −29     21     −9 −21     21     −1 −10     45     9 1     52     17 8     61     14 5     64     6 0     44     −6 −13     35     −18 −26     34     −22 −31 Average max. and min. temperatures in °C Precipitation totals in mm Source: SHMI[15]
Imperial conversion J F M A M J J A S O N D     0.9     −13 −29     0.7     −11 −27     0.8     1 −20     0.8     16 −6     0.8     30 14     1.8     48 34     2     63 46     2.4     57 41     2.5     43 32     1.7     21 9     1.4     0 −15     1.3     −8 −24 Average max. and min. temperatures in °F Precipitation totals in inches

Östersund, Sweden
Climate chart (explanation)
J F M A M J J A S O N D     19     −6 −13     16     −4 −12     14     1 −8     20     5 −3     23     13 3     47     18 8     61     19 10     48     17 9     34     12 5     25     6 1     19     0 −5     18     −3 −10 Average max. and min. temperatures in °C Precipitation totals in mm Source: yr.no
Imperial conversion J F M A M J J A S O N D     0.7     22 9     0.6     25 11     0.6     33 18     0.8     42 27     0.9     55 37     1.9     64 46     2.4     66 50     1.9     63 48     1.3     53 41     1     44 34     0.7     32 23     0.7     26 15 Average max. and min. temperatures in °F Precipitation totals in inches

Oulu, Finland
Climate chart (explanation)
J F M A M J J A S O N D     33     −6 −14     28     −6 −13     23     −1 −9     34     6 −3     32     13 3     49     18 9     70     21 12     65     18 10     57     13 5     46     6 1     41     0 −6     36     −4 −11 Average max. and min. temperatures in °C Precipitation totals in mm Source: Tilastokeskus: Tilastoja Suomen ilmastosta 1981-2010
Imperial conversion J F M A M J J A S O N D     1.3     21 8     1.1     22 8     0.9     30 16     1.3     42 27     1.3     55 38     1.9     64 48     2.8     70 54     2.6     65 50     2.2     55 42     1.8     42 33     1.6     31 22     1.4     25 13 Average max. and min. temperatures in °F Precipitation totals in inches

See also

• Boreal ecology
• Boreal forest
• Plants of continental subarctic climate
• Köppen climate classification
• Subantarctic

References

1. Stepanova, N.A. (1958). "On the Lowest Temperatures on Earth" (PDF). Monthly Weather Review. 86 (1): 6–10. Bibcode:1958MWRv...86....6S. doi:10.1175/1520-0493(1958)086<0006:OTLTOE>2.0.CO;2. Retrieved 4 January 2018.
2. Subarctic Division Archived 2010-01-05 at the Wayback Machine
3. Mount Washington Observatory: Normals, Means, and Extremes, Retrieved July 1, 2009.
4. "Subarctic Division". www.fs.fed.us. Retrieved 2020-01-04.
5. Geography of climate Archived 2012-02-06 at the Wayback Machine
6. Peel, M. C.; Finlayson, B. L.; McMahon, T. A. (2007). "Updated Köppen-Geiger Climate Map of the World". Hydrology and Earth System Sciences. Copernicus Publications. doi:10.5194/hess-11-1633-2007. Retrieved 23 October 2019.
7. "Canadian Climate Normals 1971–2000". Environment Canada. Retrieved 2009-10-14.
8. "Moosonee UA Station". Canadian Climate Normals 1971–2000. Environment Canada. 2011-01-19. Retrieved 2012-03-24.
9. "Normwert-Tabellen 1961–1990" (in German, French, and Italian). MeteoSchweiz. Archived from the original on 2009-06-27. Retrieved 2009-10-15.
10. "Luleå, SWE". World Weather Information. Archived from the original on 2006-05-14. Retrieved 2009-10-17.
11. "Nederbörd, normalvärden 1961–90". SMHI. Archived from the original on 2007-10-20. Retrieved 2009-10-17.
12. "Mohe County, 1971-2000". Weather.com.cn. Retrieved 2011-09-12.
13. "Lukla, Nepal Travel Weather Averages (Weatherbase)". Retrieved 2015-08-11.
14. "Crater Lake Nat'l Park H, Oregon Period of Record Climate Summary". Western Regional Climate Center. Retrieved 2012-04-17.
15. "Norilsk Weather Averages and Climate". weather2travel. Retrieved 2012-04-18.