The Fujita scale is a scale used for rating tornado strength, based on the damage tornadoes cause on human-built buildings and vegetation. The official Fujita scale category is determined by meteorologists (and engineers) after a ground and/or aerial damage inspection; also including analysis of available sources such as eyewitness accounts and damage images and/or videos. It was replaced with the Enhanced Fujita scale in the United States in February 2007.
|Scale||Wind speed*||Relative frequency||Common Damage Path Width (meters)[note 1]||Example of Damage|
|F0||40–72||64–116||38.9%||10 - 50||Small damage.
Some damage to chimneys; branches broken off trees; sign boards damaged.
|F1||73–112||117–180||35.6%||30 - 150||Medium damage.|
|F2||113–157||181–253||19.4%||110 - 250||Fairly bad damage.
Roofs come off frame houses; mobile homes destroyed; big trees snapped or uprooted.
|F3||158–206||254–332||4.9%||200 - 500||Bad damage.|
|F4||207–260||333–418||1.1%||400 - 900||Very bad damage.
Well-made houses leveled; buildings and other things with weak foundations blown away very far; skyscrapers and highrises destroyed.
|F5||261–318||419–512||<0.1%||1100 ~||Worst damage.|
Other F0 Rated Tornadoes: Waterspout
- Stronger tornadoes are usually bigger, but they don't have to be. Some weak tornadoes are big and wide. Some very strong tornadoes are skinny.