The Beaufort wind scale rates wind strength from 0 (calm) to 12 (hurricane) based on observed effects, with the wind speed in km/h.
| Force | Description | Speed (km/h) | Effects on land |
|---|---|---|---|
| 0 | Calm | Less than 1 | Smoke rises vertically |
| 1 | Light air | 1 – 5 | Smoke drifts |
| 2 | Light breeze | 6 – 11 | Leaves rustle |
| 3 | Gentle breeze | 12 – 19 | Twigs move, flags flap |
| 4 | Moderate breeze | 20 – 28 | Dust and small branches |
| 5 | Fresh breeze | 29 – 38 | Small trees sway |
| 6 | Strong breeze | 39 – 49 | Large branches move |
| 7 | Near gale | 50 – 61 | Whole trees move |
| 8 | Gale | 62 – 74 | Twigs break off trees |
| 9 | Strong gale | 75 – 88 | Slight structural damage |
| 10 | Storm | 89 – 102 | Trees uprooted |
| 11 | Violent storm | 103 – 117 | Widespread damage |
| 12 | Hurricane | 118+ | Devastation |