Wind Force Table - Wind Force, Wind Speed and Designation
The wind force is measured in Beaufort, Bft. This scale is used worldwide up to level 12. The expansion with levels 13 to 17 is only used in China and Taiwan, where such wind forces can occur during typhoons. There are several other locally used storm scales, the most important of which is the Saffir-Simpson Hurricane Scale from the US National Hurricane Center. There are other special scales for tropical cyclones, which can reach strengths similar to hurricanes.
Wind forces on the Beaufort scale
| Bft | km/h | Designation | Sea |
|---|---|---|---|
| 0 | 0 - 1 | Calm | - |
| 1 | 1 - 5 | Light air | Ripples |
| 2 | 6 - 11 | Light breeze | Small wavelets |
| 3 | 12 - 19 | Gentle breeze | Large wavelets |
| 4 | 20 - 28 | Moderate breeze | Small waves |
| 5 | 29 - 38 | Fresh breeze | Moderate waves |
| 6 | 39 - 49 | Strong breeze | Large waves |
| 7 | 50 - 61 | High wind, moderate gale, near gale | White foam |
| 8 | 62 - 74 | Gale, fresh gale | Moderately high waves |
| 9 | 75 - 88 | Strong/severe gale | High waves |
| 10 | 89 - 102 | Storm, whole gale | Very high waves |
| 11 | 103 - 117 | Violent storm | Exceptionally high waves |
| 12 | 118 - (133) | Hurricane force | Completely white |
| 13 | 134 - 149 | Typhoon | |
| 14 | 150 - 166 | Typhoon | |
| 15 | 167 - 183 | Typhoon | |
| 16 | 184 - 202 | Typhoon | |
| 17 | 203 - | Typhoon |
Saffir Simpson Hurricane Scale
| Designation | km/h |
|---|---|
| Tropical depression | - 63 |
| Tropical storm | 63 - 118 |
| Hurricane category 1 | 119 - 153 |
| Hurricane category 2 | 154 - 177 |
| Hurricane category 3 | 178 - 208 |
| Hurricane category 4 | 209 - 251 |
| Hurricane category 5 | 251 - |
Speeds are given in kilometers per hour. Meters per second are used scientifically, miles per hour are used in the USA and knots are used on the high seas.
The highest linear wind speed recorded to date was measured by cyclone Olivia on April 10, 1996 on Barrow Island, Western Australia: 408 km/h. The rotation speed of a tornado can be even higher, maximum values of up to 500 km/h can be reached here.
Storms are strong winds caused by differences in air pressure and temperature. The sun heats the Earth's surface unevenly. Some areas heat up faster than others. Warm air rises because it is lighter than cold air. This creates an area of low air pressure near the ground. Cooler air flows in from areas of higher air pressure to equalize the difference. This movement of air is what we call wind.
When the difference in air pressure is particularly large, the wind becomes stronger. Over the ocean, warm, moist air can rise and form clouds. Due to the Earth's rotation, the air begins to rotate, creating a whirlwind. Depending on the region and intensity, these whirlwinds are called hurricanes, typhoons, or cyclones. They usually form over warm ocean water and can develop into powerful storms if they absorb enough energy.
Thunderstorms can also cause strong winds. During a thunderstorm, warm, moist air rises rapidly and cools. This creates strong updrafts and downdrafts that can lead to violent gusts. In extreme cases, tornadoes form, characterized by rotating columns of air and possessing enormous destructive power.
Due to climate change, the energy content of the atmosphere is increasing, which can make storms more intense.
Last updated on 01/20/2026. Author: Jürgen Kummer
Physics commonly uses SI units. Here is a calculator to convert lengths, temperature, pressure, speed and other units.