Beaufort force (max gust)
0 Calm (<0.5 m/s)
1 Light air (0.5-1.6)
2 Light breeze (1.6-3.4)
3 Gentle breeze (3.4-5.5)
4 Moderate breeze (5.5-8.0)
5 Fresh breeze (8.0-10.8)
6 Strong breeze (10.8-13.9)
7 Near gale (13.9-17.2)
8 Gale (17.2-20.8)
9 Strong gale (20.8-24.5)
10 Storm (24.5-28.5)
11 Violent storm (28.5-32.7)
12 Hurricane force (>32.7)