It is impossible to sum up Canada’s climate in one easy-to-understand sentence, given the country’s size and geographical diversity, but the phrase “frozen north” would be a reasonable first approximation. In most places, winters are harsh, similar to Russia. The most populous region, southern Ontario, has a milder climate, similar to that of the neighbouring Midwest and northeastern United States. Iqaluit, the capital of Nunavut, lies just south of the Arctic Circle and remains very cold, except in July and August, when the average July high temperature is only 12°C. In contrast, the coast of British Columbia is very mild for its latitude and stays above freezing for most of the winter, but it is not far from some of the continent’s largest mountain glaciers.
Most major Canadian cities are less than 200 km from the US border (Edmonton, Calgary, Halifax and St. John’s are notable exceptions). Visitors to most cities are unlikely to experience the weather that accompanies travel to the more remote northern or mountainous regions often depicted on postcards of Canada. Summers in the more populated areas of Canada are generally short and hot. Summer temperatures above 35 °C are not uncommon in southern Ontario, the southern prairies and the southern backcountry of British Columbia, with Osoyoos being Canada’s hotspot for average daily highs. Toronto’s climate is only slightly cooler than that of many major cities in the northeastern US, and summers in the southern parts of Ontario and Quebec (including Montreal) are often hot and humid. In contrast, humidity in the western interior is often low, even in hot summer weather, and cooling tends to occur at night. In winter, eastern Canada, especially the Atlantic provinces, is sometimes exposed to adverse weather systems from the United States that bring snow, strong winds, rain, sleet and temperatures below -10°C (14°F).
In many inland towns, especially in the prairies, there are extreme, sometimes very rapid, variations in temperature. Due to the dry climate (drier in the west than in the east in the southern prairies) there are many hours of sunshine, in the range of 2300 to 2600 hours per year.
Winnipeg has warm summers with episodes of aggressive humidity, but experiences very cold winters where temperatures around -40°C (-40°F) are not uncommon. The warmest temperature ever officially recorded in Canada was 113°F (45°C) in southern Saskatchewan, while the coldest was -81°F (-63°C) in Snag, Yukon. Summer storms in the Prairies and Ontario can be severe, sometimes bringing high and destructive winds, hail and, rarely, tornadoes. On the west coast of British Columbia, the cities of Vancouver and Victoria are much more temperate with very little snow, low average wind speeds and temperatures rarely below 0°C or above 27°C (32-80°F), but receive heavy precipitation in winter followed by dry, sunny and pleasant summers.
The average temperature in Canada is generally colder than in the United States and Western Europe as a whole. So pack a warm jacket if you are travelling between October and April, and sooner or later if you are visiting hilly or mountainous terrain or northern regions. In most of the country, maximum summer temperatures tend to be well above 15°C and usually range between 20 and 30°C.