Land and Resources, Climate
permafrost region, thermokarst, Canadian Arctic Archipelago, warm ocean currents, Rocky Mountain foothills
Because of its size, Canada has a great variety of climatic conditions. Part of the mainland and most of the Canadian Arctic Archipelago are within Earth’s north frigid zone; the remainder of the country lies in the northern half of the north temperate zone. Climatic conditions range from the extreme cold of the Arctic regions to the moderate temperatures of more southerly latitudes. Average summer temperatures range from 8°C (46°F) in the far north to more than 22°C (72°F) in some parts of the far south. Average January temperatures range from -35°C (-31°F) in the far north to 3°C (37°F) in southwestern British Columbia. Similarly, precipitation ranges from near-desert conditions of less than 300 mm (12 in) per year in the far north to very wet conditions of more than 2,400 mm (more than 90 in) in parts of the west coast. Thus we cannot speak of a single Canadian climate, but rather of several regional climates.
In the Atlantic provinces, the ocean lessens the extremes of winter cold and summer heat but also causes considerable fog and precipitation. The Pacific coast, which is influenced by warm ocean currents and moisture-laden winds, has mild summers and winters, high humidity, and abundant precipitation. In the Canadian Cordillera, the higher western slopes of certain uplifts, particularly the Selkirks and the Rockies, receive sizable amounts of rain and snow. The eastern slopes and the central plateau receive little precipitation. In the eastern Canadian Cordillera, the chinook, a warm, dry westerly wind, makes winters substantially less severe in the Rocky Mountain foothills and adjoining plains. The Prairie provinces (Alberta, Manitoba, and Saskatchewan) are marked by the most extreme ranges of summer heat and winter cold in Canada. Eastern Canada (Ontario and Quebec), which also has great variations in heat and cold, is the snowiest region in Canada.
Climate has been a factor in the development of Canada because people have settled where temperatures are warmest and agricultural growing seasons longest. Climate also influences vegetation, producing, for example, the rain forest of coastal British Columbia. Southern Ontario and southwestern British Columbia have the mildest climates and greatest population densities in Canada. In contrast, the central and northern regions are sparsely populated. The permafrost region in the north poses great challenges for settlement and development. Yukon Territory, the Northwest Territories, the Nunavut Territory, northern Quebec and Labrador, and the far northern areas of Ontario and Manitoba are all affected by this condition. Houses, roads, runways, and pipelines require special, expensive adaptations. Water and sewage lines are especially troublesome to maintain. Permafrost also makes mining and other forms of development more difficult and environmentally damaging. Disruption of the environment through development can induce thermokarst, the formation of thaw lakes into which buildings can sink.
Article key phrases: