Weather Tornado Facts Tornadoes, violently rotating columns of air extending from a thunderstorm to the ground, are among nature's most virulent storms. The worst tornadoes are capable of tremendous destruction with wind speeds of 250 miles per hour or more.
Tornadoes can occur anywhere in the U.S. at any time of the year.
In the southern states, the peak tornado season is March through May, while peak months in the northern states are during the summer.