In which U.S. region are the tornadoes most frequent?
in the Mid Eastern states
they occur evenly throughout the U.S.
Tornado Alley is a colloquial term for the area of the United States where tornadoes are most frequent. The term was first used in 1952 as the title of a research project to study severe weather in areas of Texas, Oklahoma, Kansas, South Dakota, Iowa, Illinois, Missouri, Nebraska, Colorado, North Dakota, and Minnesota.