Convert wind speed between all common units including the Beaufort scale.
| Force | km/h | Description |
|---|---|---|
| 0 | < 1 | Calm |
| 1 | 1–5 | Light Air |
| 2 | 6–11 | Light Breeze |
| 3 | 12–19 | Gentle Breeze |
| 4 | 20–28 | Moderate Breeze |
| 5 | 29–38 | Fresh Breeze |
| 6 | 39–49 | Strong Breeze |
| 7 | 50–61 | Near Gale |
| 8 | 62–74 | Gale |
| 9 | 75–88 | Strong Gale |
| 10 | 89–102 | Storm |
| 11 | 103–117 | Violent Storm |
| 12 | > 118 | Hurricane Force |
Wind speed is the rate at which air moves past a given point. It is measured using an instrument called an anemometer. Wind speed is important in meteorology, aviation, sailing, construction, and many outdoor activities. Different countries and industries use different units to measure wind speed.
The Beaufort scale is an empirical measure that relates wind speed to observed conditions on land and at sea. It was developed in 1805 by Irish hydrographer Francis Beaufort. The scale ranges from 0 (calm, mirror-like sea) to 12 (hurricane force, severe devastation). It is still widely used by meteorologists and sailors today.
A knot is a unit of speed equal to one nautical mile per hour, approximately 1.852 km/h. It is commonly used in aviation and maritime contexts to measure wind and vessel speed.
Wind speeds above 50 km/h (Beaufort 7, Near Gale) can make walking difficult and cause minor structural damage. Speeds above 89 km/h (Beaufort 10, Storm) are considered dangerous and can cause significant damage.
A hurricane (Beaufort 12) has sustained wind speeds of 118 km/h or more. Extreme hurricanes can reach wind speeds exceeding 250 km/h.