| Scale Value |
From mph |
To mph |
Tornado Intensity | Damage examples |
|---|---|---|---|---|
| F0 | 40 | 72 | Gale | Breaks branches off trees Pushes over shallow-rooted trees Damages sign boards Some damage to chimneys |
| F1 | 73 | 112 | Moderate | The lower limit is the beginning of hurricane wind speed Peels surface off roofs Mobile homes pushed off foundations or overturned Attached garages may be destroyed Moving autos pushed off the road |
| F2 | 113 | 157 | Significant | Considerable damage Roofs torn off frame houses Mobile homes demolished Large trees snapped or uprooted Boxcars pushed over Light object missiles generated |
| F3 | 158 | 206 | Severe | Roof and some walls torn off well constructed houses Most trees in forest uprooted Trains overturned |
| F4 | 207 | 260 | Devastating | Well-constructed houses leveled Structures with weak foundations blown off some distance Cars thrown and large missiles generated |
| F5 | 261 | 318 | Incredible | Trees debarked Strong frame houses lifted off foundations and carried considerable distances Automobile sized missiles fly through the air in excess of 100 meters Steel re-inforced concrete structures badly damaged |
| F6 | 319 | 379 | Inconceivable | These winds are very unlikely. The small area of damage they might produce would probably not be recognizable along with the mess produced by F4 and F5 wind that would surround the F6 winds. Missiles, such as cars and refrigerators would do serious secondary damage that could not be directly identified as F6 damage. If this level is ever achieved, evidence for it might only be found in some manner of ground swirl pattern, for it may never be identifiable through engineering studies. |