Tornado climatology
Tornadoes have been recorded on all continents except Antarctica and are most common in the middle latitudes where conditions are often favorable for convective storm development. The United States has the most tornadoes of any country, as well as the strongest and most violent tornadoes. A large portion of these tornadoes form in an area of the central United States popularly known as Tornado Alley. Other areas of the world that have frequent tornadoes include significant portions of Europe, South Africa, Philippines, Bangladesh, parts of Argentina, Uruguay, and southern and southeast Brazil, northern Mexico, New Zealand, and far eastern Asia.
List of Canadian tornadoes and tornado outbreaks
Ontario, Alberta, Manitoba and Saskatchewan all average 15 tornadoes per season, followed by Quebec with fewer than 10. New Brunswick and the British Columbia Interior are also recognized tornado zones. All other provinces and territories have significantly less threat from tornadoes. The peak season in Canada is in the summer months when clashing air masses move north, as opposed to the spring season in the United States southern-central plains, although tornadoes in Canada have occurred in spring, fall and very rarely winter.