Tornado Alley
States such as Missouri, Iowa, Minnesota, Wisconsin, Illinois, Indiana, and western Ohio are sometimes included in Tornado Alley. Research suggests that tornadoes are becoming more frequent in the northern parts of Tornado Alley where it reaches the Canadian prairies.
Canada Tornado Alley
Although the official boundaries of the Canadian Tornado Alleys are not clearly defined, its core extends from Central Alberta through Saskatchewan, Southern Manitoba and Northwestern Ontario. A second tornado alley extends from Michigan to Central Ontario and from Central Ontario to Southwestern Quebec. The Canadian Prairies are often considered part of the United States tornado alley.