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.
Tornado Alley
The average tornado usually only stays on ground for 5 minutes but these figures, reported by the National Climatic Data Center for the period between 1991 and 2010, show the seventeen U.S. states with the highest average number of tornadoes per per year.
After the U.S., Canada gets the most tornadoes in the world. The average number of tornadoes per is highest in the southern parts of Alberta, Saskatchewan, and Manitoba, as well as Southern Ontario. Northern Ontario between the Manitoba border and the Lake Superior lakehead is also prone to severe tornadoes, but tornadoes in this area are believed to be underestimated due to the extremely low population in this region.