Bft | type | m/s | kts | km/h | mph |
0 | Calm | <0.2 | < 1 | < 1 | < 1 |
1 | Light Air | 0.3 - 1.5 | 1 - 3 | 1 - 5 | 1 - 3 |
2 | Light Breeze | 1.6 - 3.3 | 4 - 6 | 6 - 11 | 4 - 7 |
3 | Gentle Breeze | 3.4 - 5.4 | 7 - 10 | 12 - 19 | 8 - 12 |
4 | Moderate Breeze | 5.5 - 7.9 | 11 - 16 | 20 - 28 | 13 - 18 |
5 | Fresh Breeze | 8.0 - 10.7 | 17 - 21 | 29 - 38 | 19 - 24 |
6 | Strong Breeze | 10.8 - 13.8 | 22 - 27 | 39 - 49 | 25 - 31 |
7 | Moderate Gale | 13.9 - 17.1 | 28 - 33 | 50 - 61 | 32 - 38 |
8 | Fresh Gale | 17.2 - 20.7 | 34 - 40 | 62 - 74 | 39 - 46 |
9 | Strong Gale | 20.8 - 24.4 | 41 - 47 | 75 - 88 | 47 - 54 |
10 | Whole Gale/Storm | 24.5 - 28.4 | 48 - 55 | 89 - 102 | 55 - 63 |
11 | Violent Storm | 28.5 - 32.6 | 56 - 63 | 102 - 117 | 64 - 74 |
12 | Hurricane Force | >32.6 | >63 | >117 | >74 |