Humid continental climate

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Humid continental climate worldwide
Humid continental climate worldwide

The humid continental climate is a climate found over large areas of land masses in the temperate regions of the mid-latitudes where there is a zone of conflict between polar and tropical air masses. The humid continental climate is marked by variable weather patterns and a large seasonal temperature variance. The seasonal temperature variance can be as great as 33° Celsius, but is typically about 15 - 22°C (27-40° Fahrenheit). The temperature difference between the warmest and coldest months increases as one moves further inland and away from the moderating influence of the ocean. Places with a hottest month temperature above 10 °C and a coldest month temperature below -3°C, and which do not meet the criteria for an arid climate, are classified as continental.[1]

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[edit] Dfa: Hot (or very warm) summer subtype

Within North America it includes much of the eastern and midwestern portions of the United States and extreme southern Ontario,Canada from the Atlantic to the 100th meridian west and generally in the range of 39°N to 44°N latitude; precipitation increases the further eastward in this zone and is less seasonally uniform in the west; this area includes the following regions:

Some of the major North American cities in this zone:

The 0°C (32°F) isotherm (freeze line) or the -3°C (26.6°F) isotherms (persistent snow line) are the possible lines dividing the humid continental and the humid subtropical climates. The Koppen climate classification, the most popular climate classification, uses -3°C (26.6°F). In between these lines are the following places:

Some states in this zone:

The western states of the central United States (namely Montana, Wyoming, parts of southern Idaho, parts of Colorado, western Nebraska, and western areas of North and South Dakota) have thermal regimes which fit the Dfa climate type, but are quite dry, and are generally grouped with the steppe (Bsk) climates.

Outside of North America the Dfa climate type is present near the Black Sea in southern Ukraine, the Southern Federal District of Russia, Moldova, and parts of eastern Romania, but tends to be drier, or even semi-arid, in these places. Tohoku in Japan between Tokyo and Hokkaidō also has a climate with Köppen classification Dfa, but is wetter even than that part of North America with this climate type. A variant which has dry winters and hence much lower snowfall with monsoonal type summer rainfall is to be found in north-eastern China including coastal regions of the Yellow Sea and over much of the Korean Peninsula; it has the Köppen classification Dwa. Much of central Asia, northwestern China, and southern mongolia have a thermal regime similar to that of the Dfa climate type, but these regions receive so little precipitation that they are more often classified as steppes (BSk) or deserts (BWk).

It appears nowhere within the Southern Hemisphere, which has no large landmasses so situated in the middle latitudes that allow the combination of hot summers and at least one month of sub-freezing temperatures.

Cities outside North America with this climate include:

[edit] Dfb: Warm summer subtype

The warm summer subtype (Köppen: Dfb) lies north of the hot summer subtype; in North America, from about 44°N to 50°N in the east but places of adequate precipitation as far north as 54°N in the Canadian Prairie Provinces and below 40°N in the high Appalachians, separated by the 22°C isotherm for the warmest month from the Dfa climates (which passes near Minneapolis, Minnesota and Grand Rapids, Michigan). Summer temperatures in this zone typically average between 70 F and 85 F (21°C-29°C) during the daytime.

It includes the following places:


In Canada, it includes these areas:

Some of the major cities in this zone:

It is also found in central Scandinavia. East central Europe (east of Germany and Hungary) is a warm summer subtype with less severe winters, similar to the winters of the hot summer subtype - the winters here are modified by the oceanic climate influence of western Europe.

The warm summer subtype is marked by mild summers, long cold winters and less precipitation than the hot summer subtype, however, short periods of extreme heat are not uncommon. In this region, summers shorten and are cooler, and winters become longer and colder toward the north parts of this zone. Northern Japan has a similar climate.

Much of Mongolia and parts of southern Siberia has a thermal regime fitting this climate, but it has steppe or desert like precipitation and so is not really considered to be a humid continental climate.

Countries with this climate:

In the Southern Hemisphere it exists only in the Southern Alps of New Zealand and perhaps as isolated microclimates of the southern Andes of Chile and Argentina.

Cities with such climates outside North America include:

A dry-winter variant (Köppen: Dwb) is to be found in northeastern China, northern Korea and the Southeastern region of Russian Far East, as at Vladivostok and Chongjin, North Korea, and Harbin, China. This variant does not exist in the Southern Hemisphere.

[edit] Subarctic climate

Near 50°N in North America (except north of 55°N in Alberta and British Columbia) and eastern Asia (60°N or further north in Europe), the climate grades into a subarctic climate (Köppen: Dfc, Dwc), poleward of which the summers (seasons with temperatures above 10°C) are shorter than four months.

This climate appears nowhere in the southern hemisphere because of the complete absence of inland areas isolated from oceanic waters between 45° and 55° south latitude.

[edit] References

  1. ^ Peel, M. C. and Finlayson, B. L. and McMahon, T. A. (2007). "Updated world map of the Köppen-Geiger climate classification". Hydrol. Earth Syst. Sci. 11: 1633-1644. ISSN 1027-5606.  (direct: Final Revised Paper)