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.
Tornado climatology
South America has its own , composed of central and northern Argentina, southern and southeast Brazil, Uruguay, and part of Paraguay, and is considered the second highest frequency tornado region in the world. Argentina has areas with high tornadic activity, and the strongest tornadoes in the southern hemisphere like the F5 in San Justo, and the in Buenos Aires with more than 300 tornadoes registered in less than 24 hours.