A tornado is a rapidly rotating column of air that extends vertically from the Earth's surface to the base of a cumulonimbus or cumulus cloud. A condensation funnel often originates from the cloud base while a cloud of rotating debris and dust forms close to the ground.
Tornadoes most commonly occur in North America particularly in central and southeastern regions known as Tornado Alley. The United States has by far the most tornadoes of any country in the world with an average of about 1,200 per year.
The Fujita scale rates tornadoes by damage caused and has been replaced in some countries by the Enhanced Fujita Scale. An F5 or EF5 tornado rips buildings off their foundations and can deform large skyscrapers.
The Daultipur-Salturia Tornado in Bangladesh on the 26th of April 1989 killed approximately 1,300 people. This remains the deadliest tornado in world history as of 2025.
The first public tornado warnings were issued in 1950 before detection relied solely on someone seeing a tornado on the ground. Hook echoes associated with tornadoes were confirmed in 1953 to improve early warning systems.