Beaufort Scale Overview
| Bft | Name | km/h | m/s | Knots | Description |
|---|---|---|---|---|---|
| Bft 0 | Calm | 0-1 | 0-0.2 | 0-1 | Smoke rises vertically |
| Bft 1 | Light air | 2-5 | 0.3-1.5 | 1-3 | Wind direction shown by smoke drift |
| Bft 2 | Light breeze | 6-11 | 1.6-3.3 | 4-6 | Leaves rustle, wind felt on face |
| Bft 3 | Gentle breeze | 12-19 | 3.4-5.4 | 7-10 | Leaves and small twigs in constant motion |
| Bft 4 | Moderate breeze | 20-28 | 5.5-7.9 | 11-16 | Branches move, loose paper lifted from the ground |
| Bft 5 | Fresh breeze | 29-38 | 8-10.7 | 17-21 | Larger branches move, whistling in telegraph wires |
| Bft 6 | Strong breeze | 39-49 | 10.8-13.8 | 22-27 | Large branches move, umbrellas difficult to use |
| Bft 7 | Near gale | 50-61 | 13.9-17.1 | 28-33 | Whole trees sway, walking against the wind is difficult |
| Bft 8 | Gale | 62-74 | 17.2-20.7 | 34-40 | Twigs break off, walking is seriously impeded |
| Bft 9 | Strong gale | 75-88 | 20.8-24.4 | 41-47 | Branches break, slight damage to buildings |
| Bft 10 | Storm | 89-102 | 24.5-28.4 | 48-55 | Trees uprooted, considerable damage to buildings |
| Bft 11 | Violent storm | 103-117 | 28.5-32.6 | 56-63 | Widespread damage |
| Bft 12 | Hurricane force | 118-200 | 32.7-56 | 64-108 | Severe and extensive damage |
Smoke rises vertically
Wind direction shown by smoke drift
Leaves rustle, wind felt on face
Leaves and small twigs in constant motion
Branches move, loose paper lifted from the ground
Larger branches move, whistling in telegraph wires
Large branches move, umbrellas difficult to use
Whole trees sway, walking against the wind is difficult
Twigs break off, walking is seriously impeded
Branches break, slight damage to buildings
Trees uprooted, considerable damage to buildings
Widespread damage
Severe and extensive damage
About the Beaufort Scale
The Beaufort scale is a scale for classifying wind force. It was developed in 1806 by British Admiral Sir Francis Beaufort and remains an important reference in meteorology and nautical science today.
The scale ranges from 0 (calm) to 12 (hurricane) and was originally based on the observable effects of wind on the surroundings. Today it is usually combined with precise wind speed measurements.
Important Wind Speed Units
- km/h (kilometers per hour): Common in German-speaking countries
- m/s (meters per second): Scientific standard unit
- Knots (kn): Used in shipping and aviation (1 kn = 1.852 km/h)
- mph (miles per hour): Common in the US and UK (1 mph = 1.609 km/h)
Want to understand wind?
At MeteoAcademy, you'll learn the Beaufort scale in the context of weather systems and pressure gradients.