The
humid continental climate is a
climate found over large areas of landmasses 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. Summers are often warm and humid with frequent
thunderstorms and winters can be very cold and snowy. The seasonal temperature variance is typically 25-35 °C (45-63 °F) and increases as one moves further inland and away from the moderating influence of the
ocean. Places with at least four months of average daily temperatures above and at least one month below depending on source, and which do not meet the criteria for an
arid climate, are classified as humid continental. It is most prominent over a wide section of central and eastern
North America, parts of Eastern
Europe, northwestern
Asia and areas adjacent to the
Yellow Sea, the
Korean Peninsula and Northern
Japan. It is only found in small pockets (micro climates) in the
Southern Hemisphere and in
Antarctica.
Dfa/Dwa: Hot (or very warm) summer subtype
A hot (or very warm) version of a continental climate features an average temperature of at least in its warmest month. The warmest month is usually in July, though it some cases it can be in August. Average July afternoon temperatures in this zone generally average between while the average temperature of the coldest month is or colder. In some instances, the average temperature of the coldest month can be far below . Within North America it includes much of the
eastern and
midwestern portions of the
United States and part of
southern Ontario,
Canada from the
Atlantic to the
100th meridian 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:
- Extreme western Virginia (in higher elevations)
- Most of West Virginia (except in valley areas at lower elevations)
- Extreme southwestern Maine
Some of the major North American cities in this zone:
The
isotherm (freeze line) or the 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 . In between these lines are the following places:
Some regions 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:
Dfb/Dwb: Warm summer subtype
The warm summer version of a continental climate (
Köppen: Dfb) generally lies north of the hot summer subtype. In North America, this version generally exists from about 44°N to 50°N latitude typically east of the
100th meridian. However, this version can be found as far north as 54°N in the Canadian
Prairie Provinces and below 40°N in the high
Appalachians. Areas featuring this subtype of the continental climate has an average temperature in its warmest month below 22°C. Summer temperatures in this zone typically average between during the daytime and the average winter temperatures in the coldest month are generally far below the isotherm.
It includes the following places:
In Canada, it includes these areas:
- Most of Ontario except south of Toronto and far northern regions
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, more simaliar to the winters of the hot summer subtype found in eastern North America- 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. Northern
Japan has a similar climate.
Much of
Mongolia and parts of southern
Siberia have a thermal regime fitting this climate, but they have steppe- or desert-like precipitation, and so are not really considered to have a humid continental climate.
Countries with this climate:
- Italy's and Switzerland's Alps, between 1100 and 1600 meters (Western Alps) and between 900 and 1450 meters(Eastern and Central Alps)
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:
Subarctic climate
Near 50°N in North America (except north of 55°N in Alberta, British Columbia and Saskatchewan) 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.
