Tornado climatology
The United States averaged 1,274 tornadoes per year in the last decade. April 2011 saw the most tornadoes ever recorded for any month in the US National Weather Service's history, 875; the previous record was 542 in one month. It has more tornadoes yearly than any other country and reports more violent (F4 and F5) tornadoes than anywhere else.
Tornadoes of 1997
The 1997 Benton, Arkansas tornado outbreak was a major tornado outbreak that struck portions of the central and southern United States mostly on March 1, 1997, with initial activity on February 28. Affecting areas mostly from Arkansas to Kentucky, the two-day outbreak produced 39 tornadoes and killed at least 27 people including 25 in Arkansas alone with one death in each Mississippi and Tennessee.[2] This was Arkansas' deadliest tornado outbreak since May 15, 1968, where 34 were killed in Jonesboro.[3] Over 400 others were injured during this event which was about 45% of the yearly average of tornado-related injuries in the United States.