| Decriptive Term |
Beaufort Scale Number |
Wind Speed in m/s |
Description at Sea |
| Calm |
0 |
0.0 – 0.2 |
Sea like a mirror. |
| Light Air |
1 |
0.3 – 1.5 |
Ripples with appearance of scales; no foam crests. |
| Light Breeze |
2 |
1.6 – 3.3 |
Small wavelets; crests of glassy appearance; not breaking. |
| Gentle Breeze Winds |
3 |
3.4 – 5.4 |
Large wavelets; crests begin to break; scattered whitecaps. |
| Moderate Breeze |
4 |
5.5 – 7.9 |
Small waves; becoming longer; numerous whitecaps |
| Fresh Breeze |
5 |
8.0 – 10.7 |
Moderate waves, taking longer to form; many whitecaps; some spray. |
| Strong Breeze |
6 |
10.8 – 13.8 |
Larger waves forming; whitecaps everywhere; more spray. |
| Near Gale |
7 |
13.9 – 17.1 |
Sea heaps up; white foam from breaking waves begins to be blown downwind in streaks. |
| Gale |
8 |
17.2 – 20.7 |
Moderately high waves of greater length; edges of crests begin to break into spindrift; foam is blown in well-marked streaks. |
| Strong Gale |
9 |
20.8 – 24.4 |
High waves; sea begins to roll; dense streaks of foam; spray may reduce visibility |
| Whole Gale or Storm |
10 |
24.5 – 28.4 |
Very high waves with long overhanging crests; sea appears white as foam is blown in very dense streaks; rolling is heavy and visibility is reduced. |
| Violent Storm |
11 |
28.5 – 32.6 |
Exceptionally high waves; sea covered with white foam patches; visibility further reduced. |
| Hurricane |
12 |
32.7 – 36.9 |
Air is filled with foam; sea completely white with driving spray; visibility greatly reduced. |