| 0 |
0 |
<1 kt
<1 mph
<1 km/h |
Light |
Calm |
Calm |
Sea like a mirror. |
0 |
Smoke rises vertically. |
| 1 |
2
kt
2 mph
3 km/h |
1-3 kts
1-3 mph
1-5 km/h |
Light |
Light
air |
Smooth |
Ripples with the appearance of scales
are formed, but without foam crests. |
¼ ft
0.1 m |
Direction shown by smoke but not by wind
vanes. |
| 2 |
5
kts
6 mph
9 km/h |
4-6
kts
4-7 mph
6-11 km/h |
Light |
Light
breeze |
Smooth |
Small wavelets, still short but more
pronounced, crests have a glassy appearance and do not break. |
½-1
ft
0.2 m |
Wind felt on face; leaves rustle;
ordinary vane moved by wind. |
| 3 |
9
kts
10 mph
16 km/h |
7-10
kts
8-12 mph
12-19 km/h |
Gentle |
Gentle
breeze |
Slight |
Large wavelets. Crests begin to break.
Foam of glassy appearance. |
2-3
ft
0.6 m |
Leaves and small twigs in constant
motion; wind extends light flag. |
| 4 |
13
kts
16 mph
24 km/h |
11-16
kts
13-18 mph
20-28 km/h |
Moderate |
Moderate
breeze |
Moderate |
Small waves, becoming longer. |
3½-5
ft
1 m |
Raises dust and loose paper; small
branches are moved. |
| 5 |
19
kts
22 mph
34 km/h |
17-21
kts
19-24 mph
29-38 km/h |
Fresh |
Fresh
breeze |
Rough |
Moderate waves, taking a more pronounced
long form. (Chance of some spray). |
6-8
ft
2 m |
Small trees in leaf begin to sway. |
| 6 |
24
kts
28 mph
44 km/h |
22-27
kts
25-31 mph
39-49 km/h |
Strong |
Strong
breeze |
Very
Rough |
Large
waves begin to form; the white foam crests are more extensive
everywhere. (Probably some spray). |
9½-13
ft
3 m |
Large
branches in motion; umbrellas used with difficulty. |
| 7 |
30
kts
35 mph
56 km/h |
28-33
kts
32-38 mph
50-61 km/h |
Strong |
Near
gale |
High |
Sea
heaps up and white foam from breaking waves begins to be blown in
streaks along the direction of the wind. |
13½-19
ft
4 m |
Whole
trees in motion; inconvenience felt when walking against the wind. |
| 8 |
37
kts
43 mph
68 km/h |
34-40
kts
39-46 mph
62-74 km/h |
Gale |
Gale |
Very
High |
Moderately
high waves of greater length; edges of crests begin to break into
spondrift. The foam is blown in well marked streaks along the direction
of the wind. |
18-28
ft
5.5 m |
Breaks twigs off trees; generally
impedes progress |
| 9 |
44
kts
51 mph
82 km/h |
41-47
kts
47-54 mph
75-88 km/h |
Gale |
Strong
Gale |
Very
High |
High
waves. Dense streaks of foam along the direction of the wind. Crests of
waves begin to topple, tumble and roll over. Spray may affect
visibility. |
23-32
ft
7 m |
Slight structural damage; chimney-pots
and slates removed. |
| 10 |
52
kts
59 mph
96 km/h |
48-55
kts
55-63 mph
89-102 km/h |
Whole
Gale |
Storm |
Phenomenal |
Very
high waves with long overhanging crests. The resulting foam in great
patches is blown in dense white streaks along the direction of the
wind. On the whole the surface of the sea takes a white appearance.
Visibility affected. |
29-41
ft
9 m |
Trees uprooted; considerable structural
damage. |
| 11 |
60
kts
68 mph
110 km/h |
56-63
kts
64-72 mph
103-117 km/h |
Whole
Gale |
Violent
Strom |
Phenomenal |
Exceptionally
high waves. (Small and medium sized ships might be for a time lost to
view behind the waves.) The sea is completely covered with long white
patches of foam lying along the direction of the wind. Everywhere the
edges of the wave crests are blown into froth. Visibility affected. |
39-46
ft
11.5 m |
Widespread damage; very rarely
experienced. |
| 12 |
68
kts
78 mph
124 km/h |
64-71
kts
72-82 mph
118-132 km/h |
Hurricane |
n/a |
n/a |
The air
is filled with foam and spray. Sea completely white with driving spray;
visibility very seriously affected. |
>52
ft
>14 m |
Countryside
is devastated. |