EF5 is the highest rating on the Enhanced Fujita scale.
The Enhanced Fujita, or EF, scale ranks tornado intensity from EF0 through EF5. It estimates wind speed from the damage a tornado causes, rather than measuring the wind directly in most cases. EF5 represents estimated three-second wind gusts above 200 mph, or above about 322 km/h, and is associated with extraordinary destruction.
The scale replaced the original Fujita scale in the United States in 2007. The updated system accounts more carefully for construction quality and uses 28 damage indicators, including different types of buildings, towers and trees. Survey teams compare observed damage with defined degrees of damage before assigning a rating.
EF5 does not mean a tornado has a fixed, directly measured wind speed, and the scale is not open-ended. There is no official EF6 category. The original system’s top category was F5, but an EF5 is the corresponding top category under the modern Enhanced Fujita system. Damage surveys, not appearance alone, determine the official rating.