|
Force
|
|
mph
|
|
|
knots
|
|
|
km
|
|
Description |
| 0 |
|
< 1
|
|
|
< 1
|
|
|
< 1
|
|
Calm |
| 1 |
1 |
to |
3 |
1 |
to |
3 |
1 |
to |
5 |
Light Air |
| 2 |
4 |
to |
7 |
4 |
to |
6 |
6 |
to |
11 |
Light Breeze |
| 3 |
8 |
to |
12 |
7 |
to |
10 |
12 |
to |
19 |
Gentle Wind |
| 4 |
13 |
to |
18 |
11 |
to |
16 |
20 |
to |
29 |
Moderate Wind |
| 5 |
19 |
to |
24 |
17 |
to |
21 |
30 |
to |
38 |
Fresh wind |
| 6 |
25 |
to |
31 |
22 |
to |
27 |
39 |
to |
50 |
Strong Wind |
| 7 |
32 |
to |
38 |
28 |
to |
33 |
51 |
to |
61 |
Near Gale |
| 8 |
39 |
to |
46 |
34 |
to |
40 |
62 |
to |
74 |
Gale |
| 9 |
47 |
to |
54 |
41 |
to |
47 |
75 |
to |
86 |
Strong Gale |
| 10 |
55 |
to |
63 |
48 |
to |
55 |
87 |
to |
101 |
Storm |
|
| Force |
On
Land |
| 0 |
Calm with smoke rising
vertically |
| 1 |
Smoke drifts |
| 2 |
Wind felt on face /
leaves rustle |
| 3 |
Light flags extended |
| 4 |
Flags flap |
| 5 |
Flags flap and ripple |
| 6 |
Large branches move |
| 7 |
Resistance felt when
walking |
| 8 |
Resistance felt when
walking |
| 9 |
Slight structural
damage occurs |
| 10 |
Considerable structural
damage occurs |
|
