| 0 |
0 |
0mph |
Calm |
Sea like a mirror. |
Smoke rises vertically. |
| 1 |
1-3 |
1-3mph |
Light air. |
Ripples, but no foam crests. |
Smoke drifts in the wind. |
| 2 |
4-6 |
4-7mph |
Light breeze. |
Small wavelets. |
Leaves rustle. Wind felt on face. |
| 3 |
7-10 |
8-12mph |
Gentle breeze. |
Large wavelets crests, not breaking. |
Small twigs in constant motion. Light flags extended. |
| 4 |
11-16 |
13-18mph |
Moderate wind. |
Numerous whitecaps |
Dust, leaves and loose paper raised. Small branches move |
| 5 |
17-21 |
19-24mph |
Fresh wind. |
Many whitecaps, some spray. |
Small trees sway. |
| 6 |
22-27 |
25-31mph |
Strong wind. |
Larger waves form. Whitecaps everywhere. More spray. |
Large branches move. Whistling in phone wires. Difficult to use umbrellas. |
| 7 |
28-33 |
32-38mph |
Very strong wind. |
White foam from breaking waves begins to be blown in streaks. |
Whole trees in motion. |
| 8 |
34-40 |
39-46mph |
Gale. |
Edges of wave crests begin to break into spindrift. |
Twigs break off trees. Difficult to walk. |
| 9 |
41-47 |
47-54mph |
Severe gale. |
High waves. Sea begins to roll. Spray may reduce visibility. |
Chimney pots and slates removed. |
| 10 |
48-55 |
55-63mph |
Storm. |
Very high waves with overhanging crests. Blowing foam gives sea a white appearance. |
Trees uprooted. Structural damage. |
| 11 |
56-63 |
64-72mph |
Severe storm. |
Exceptionally high waves. |
Widespread damage. |
| 12 |
63 |
73mph |
Hurricane force. |
Air filled with foam. Sea completely white. Visibility greatly reduced. |
Widespread damage. Very rarely experienced on land. |