Humid continental climate

A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900,^[1] typified by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers, and cold (sometimes severely cold in the northern areas) and snowy winters. Precipitation is usually distributed throughout the year, but often these regions do have dry seasons. The definition of this climate in terms of temperature is as follows: the mean temperature of the coldest month must be below 0 °C (32.0 °F) or −3 °C (26.6 °F) depending on the isotherm,^[2] and there must be at least four months whose mean temperatures are at or above 10 °C (50 °F). In addition, the location in question must not be semi-arid or arid. The cooler Dfb, Dwb, and Dsb subtypes are also known as hemiboreal climates. Although amount of snowfall is not a factor used in defining the humid continental climate, snow during the winter in this type of climate is almost a guarantee, either intermittently throughout the winter months near the poleward or coastal margins, or persistently throughout the winter months elsewhere in the climate zone.

Humid continental climates are generally found between latitudes 40° N and 60° N,^[3] within the central and northeastern portions of North America, Europe, and Asia. Occasionally, they can also be found at higher elevations above other more temperate climate types. They are rare in the Southern Hemisphere, limited to isolated high altitude locations, due to the larger ocean area at that latitude, smaller land mass, and the consequent greater maritime moderation.

In the Northern Hemisphere, some of the humid continental climates, typically in Hokkaido, Sakhalin Island, northeastern mainland Europe, Scandinavia, Nova Scotia, and Newfoundland are closer to the sea and heavily maritime-influenced and comparable to oceanic climates, with relatively cool summers, significant year-round precipitation (including high amounts of snow) and winters being just below the freezing mark (too cold for such a classification).^[4] More extreme and inland humid continental climates, sometimes known as "hyper-continental" climates, are found in northeast China, southern Siberia, Mongolia, Kazakhstan, most of the southern interior of Canada, and the Upper Midwest, where temperatures in the winter resemble those of adjacent subarctic climates (with long, drier, generally very cold winters) but have longer and generally warmer summers (in occasional cases, hot summers). A more moderate variety, found in places like Northern Honshu, east-central China, the Korean Peninsula, parts of Eastern Europe, parts of southern Ontario, much of the American Midwest, and the Northeast US, the climate combines hotter summer maxima and greater humidity (similar to those found in adjacent humid subtropical climates) and moderately cold winters and more intermittent snow cover (averaging somewhat below freezing, too cold for a more temperate classification), and is less extreme than the most inland hyper-continental variety.