Continental climate

Continental climate is a climate that is characterized by winter temperatures cold enough to support a fixed period of snow cover each year, and relatively moderate precipitation occurring mostly in summer, although east coast areas (chiefly in North America) may show an even distribution of precipitation. Regions containing a continental climate exist in portions of the Northern Hemisphere continents (especially North America and Asia), and also at higher elevations in other parts of the world. Only a few areas in Iran, adjacent Turkey, Afghanistan, Pakistan, and Central Asia show a winter maximum in precipitation, and this typically melts in early spring to give short-lived floods.

These regions generally have either forest or tall-grass prairie as natural ground cover and include some of the most productive farmlands in the world. All such climates have at least three months of temperatures in excess of 10 C and winters with at least one month below -3C (26.6F) or 0C (32F) depending on the classification used.

Spring-like temperatures occur in this zone between early March in the southern parts of this zone to mid April in the far northern fringes of this climate zone. Annual precipitation in this zone is usually between 24 in to 48 in, most of it in the form of snow during winter.

Most such areas fit Köppen classifications of Dfa, Dwa (cold winters, hot summers; "w" indicating very dry winters characteristic especially of China) or Dfb or Dwb (cold winters, warm summers, same distinction for winter dryness). Dry summer continental climates with significant winter precipitation maxima (Dsa and Dsb) only exist in highland areas above Mediterranean climates.

Continental climates exist where cold air masses infiltrate during the winter and warm air masses form in summer under conditions of high sun and long days. Places with continental climates are as a rule either far from any moderating effects of oceans (examples: Omaha, Nebraska, USA and Kazan, Russia) or are so situated that prevailing winds tend to head offshore (example: Boston, Massachusetts, USA; Vladivostok, Russia). Such regions get quite warm in the summer, achieving temperatures characteristic of tropical climates but are much colder than any other climates of similar latitude in the winter.

These climates grade off toward subtropical climates equator-ward where winters are less severe and semiarid climates where precipitation becomes inadequate for tall-grass prairies. In Europe these climates may grade off into oceanic climates in which the influence of moderating air masses is more marked toward the west. The subarctic climate (Köppen: Dfc), with very cold, long and dry winters, but with at least one month above 10 C, might be considered a sub-type of the continental climate.

Example of areas of the world with continental climate are the Midwestern United States, northeastern parts of the US, southern Canada, parts of China, inland areas of Spain, Korea, northern Japan, most of Russia, parts of Norway, Sweden, inner parts of Turkey, eastern Poland, Czech Republic, Austria, Slovakia, Hungary, Romania, Moldova, Ukraine, Armenia, Belarus, Lithuania, Latvia, Estonia and Finland. Continental climates do not exist in the Southern Hemisphere due to the lack of broad land masses at middle latitudes, the southernmost parts of Africa and Australia being under marine influences and southern South America being too narrow in breadth to allow cold air masses to form. Antarctica lies completely outside the middle latitudes.