Tornado Alley
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, Missouri, Nebraska, Colorado, North Dakota, and Minnesota. It is largely a media-driven term although tornado climatologists distinguish peaks in activity in certain areas and storm chasers have long recognized the Great Plains tornado belt.
Tornadoes in the United States
Although the period in which most tornadoes strike ("tornado season") is March through June, tornadoes – including violent tornadoes and major tornado outbreaks – have been documented in the United States during every month of the year. Two examples of this are when a series of tornadoes hit the state of Indiana on November 22, 1992, and injured at least nine people. Another notable non-season tornado was where a tornado struck the area of McLean County, Illinois. Even though the tornado was during a winter month, it blew 20 railroad cars off their tracks, and hauled a camper over 100 yards (91 m).