How Common Are Tornadoes in the US?

As a total number, tornadoes are more common in the United States than in any other nation. Australia is considered the runner-up, with nations such as India, Germany, Russia and the United Kingdom also the sites of many tornadoes each year. One of the worst months for US tornado activity was May 2003. During that month, 543 tornadoes were reported in the US, with the majority in the Midwest and the Deep South.

More facts about tornadoes in the US:

• A tornado is most likely to develop when an air mass that is warm and somewhat moist meets with a mass that is composed of cool and dry air. The resulting combination causes instability in the atmosphere that results in changes in wind direction and speed that create the funnels. A tornado might be somewhat small and die out within a matter of minutes or might be quite large and last for several days.


• Tornado season varies slightly from one region to the next. In the South, the period from March to May is considered the prime season for tornadoes, although some activity is expected during the hurricane season that begins in July and ends in October. People in the Plains states are more likely to see activity during May and the first part of June. The North and the upper portion of the Midwest experience peak conditions during the latter part of June and into July.


• "Tornado alley" is a term that is used to refer to a section of the Plains and Midwest reaching down to Texas. Activity in this area usually occurs but is not limited to the spring. "Dixie alley" includes parts of Tennessee, Mississippi, Kentucky and Alabama, and its tornado season occurs later in the year, with increased activity common toward the end of the Gulf Region’s hurricane season.