Tornado Alley
Although the official boundaries of Tornado Alley are not clearly defined, its core extends from northern Texas, Oklahoma, Kansas, Nebraska, into South Dakota. States such as Missouri, Iowa, Minnesota, Wisconsin, Illinois, Indiana, and western Ohio are sometimes included in Tornado Alley. Some research suggests that tornadoes are becoming more frequent in the northern parts of Tornado Alley where it reaches the Canadian prairies.
South Dakota
South Dakota summers bring frequent, sometimes severe, thunderstorms with high winds, thunder, and hail. The state's eastern part is often considered part of Tornado Alley, and South Dakota experiences an average of 30 tornadoes each year. Severe blizzards and ice storms occur often during winter.