Classification of Wind Speeds
Beaufort number |
Wind speed (km/hr) |
International description |
US Weather Bureau description |
Effect of wind on the Sea |
| 0 |
<1 |
Calm |
Light Wind |
Small wavelets |
| 1 |
1-5 |
Light Air |
Light Wind |
Small wavelets |
| 2 |
6-11 |
Light Breeze |
Light Wind
|
Small wavelets
|
| 3 |
12-19 |
Gentle Breeze |
Gentle-moderate |
Large wavelets to small waves |
| 4 |
20-28 |
Moderate Breeze |
Gentle-moderate |
Large wavelets to small waves |
| 5 |
29-38 |
Fresh Breeze |
Fresh wind |
Moderate waves, many whitecaps |
| 6 |
39-49 |
Strong gale |
Strong wind |
Large waves, many whitecaps |
| 7 |
50-61 |
Fresh Breeze |
Strong wind |
Large waves, many whitecaps |
| 8 |
62-74 |
Fresh gale |
Gale |
High waves, foam streaks |
| 9 |
75-88 |
Stong gale |
Gale |
High waves, foam streaks |
| 10 |
89-102 |
Whole gale |
Whole gale |
Very high waves, rolling sea |
| 11 |
103-117 |
Storm |
Whole gale |
Very high waves, rolling sea |
| 12-17 |
>117 |
Hurricane |
Hurricane |
Sea white with spray and foam |
Movie about the Beaufort Scale of Wind Speeds
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