Beaufort Force Wind Description m/s
0級  0 calm < 0.3
1級  1 light air 0.3-1.5
2級  2 light breeze 1.6-3.3
3級  3 gentle breeze 3.4-5.4
4級  4 moderate breeze 5.5-7.9
5級  5 fresh breeze 8.0-10.7
6級  6 strong breeze 10.8-13.8
7級  7 near gale 13.9-17.1
8級  8 gale 17.2-20.7
9級  9 strong gale 20.8-24.4
10級 10 storm 24.5-28.4
11級 11 violent storm 28.5-32.6
12級 ≥ 12 hurricane ≥ 32.7