boat24.com (english)Beaufort scale
| Beaufort number | Description | Wind speed | Wave height | Sea conditions | Land conditions |
|---|---|---|---|---|---|
| 0 | Calm | < 1 km/h | 0 m | Flat. | Calm. Smoke rises vertically. |
| < 1 mph | |||||
| < 1 kn | 0 ft | ||||
| < 0.3 m/s | |||||
| 1 | Light air | 1.1-5.5 km/h | 0-0.2 m | Ripples without crests. | Smoke drift indicates wind direction, still wind vanes. |
| 1-3 mph | |||||
| 1-2 kn | 0-1 ft | ||||
| 0.3-1.5 m/s | |||||
| 2 | Light breeze | 5.6-11 km/h | 0.2-0.5 m | Small wavelets. Crests of glassy appearance, not breaking | Wind felt on exposed skin. Leaves rustle, vanes begin to move. |
| 4-7 mph | |||||
| 3-6 kn | 1-2 ft | ||||
| 1.6-3.4 m/s | |||||
| 3 | Gentle breeze | 12-19 km/h | 0.5-1 m | Large wavelets. Crests begin to break; scattered whitecaps | Leaves and small twigs constantly moving, light flags extended. |
| 8-12 mph | |||||
| 7-10 kn | 2-3.5 ft | ||||
| 3.4-5.4 m/s | |||||
| 4 | Moderate breeze | 20-28 km/h | 1-2 m | Small waves with breaking crests. Fairly frequent white horses. | Dust and loose paper raised. Small branches begin to move. |
| 13-17 mph | |||||
| 11-15 kn | 3.5-6 ft | ||||
| 5.5-7.9 m/s | |||||
| 5 | Fresh breeze | 29-38 km/h | 2-3 m | Moderate waves of some length. Many white horses. Small amounts of spray. | Branches of a moderate size move. Small trees in leaf begin to sway. |
| 18-24 mph | |||||
| 16-20 kn | 6-9 ft | ||||
| 8.0-10.7 m/s | |||||
| 6 | Strong breeze | 39-49 km/h | 3-4 m | Long waves begin to form. White foam crests are very frequent. Some airborne spray is present. | Large branches in motion. Whistling heard in overhead wires. Umbrella use becomes difficult. Empty plastic garbage cans tip over. |
| 25-30 mph | |||||
| 21-26 kn | 9-13 ft | ||||
| 10.8-13.8 m/s | |||||
| 7 |
High wind, Moderate gale, Near gale |
50-61 km/h | 4-5.5 m | Sea heaps up. Some foam from breaking waves is blown into streaks along wind direction. Moderate amounts of airborne spray. | Whole trees in motion. Effort needed to walk against the wind. |
| 31-38 mph | |||||
| 27-33 kn | 13-19 ft | ||||
| 13.9-17.1 m/s | |||||
| 8 |
Gale, Fresh gale |
62-74 km/h | 5.5-7.5 m | Moderately high waves with breaking crests forming spindrift. Well-marked streaks of foam are blown along wind direction. Considerable airborne spray. | Some twigs broken from trees. Cars veer on road. Progress on foot is seriously impeded. |
| 39-46 mph | |||||
| 34-40 kn | 18-25 ft | ||||
| 17.2-20.7 m/s | |||||
| 9 | Strong gale | 75-88 km/h | 7-10 m | High waves whose crests sometimes roll over. Dense foam is blown along wind direction. Large amounts of airborne spray may begin to reduce visibility. | Some branches break off trees, and some small trees blow over. Construction/temporary signs and barricades blow over. |
| 47-54 mph | |||||
| 41-47 kn | 23-32 ft | ||||
| 20.8-24.4 m/s | |||||
| 10 |
Storm,The names "storm" and "hurricane" on the Beaufort scale refer only to wind strength, and do not necessarily mean that other severe weather (for instance, a thunderstorm or tropical cyclone) is present. To avoid confusion, strong wind warnings will often speak of e.g. "hurricane-force winds". Whole gale |
89-102 km/h | 9-12.5 m | Very high waves with overhanging crests. Large patches of foam from wave crests give the sea a white appearance. Considerable tumbling of waves with heavy impact. Large amounts of airborne spray reduce visibility. | Trees are broken off or uprooted, saplings bent and deformed. Poorly attached asphalt shingles and shingles in poor condition peel off roofs. |
| 55-63 mph | |||||
| 48-55 kn | 29-41 ft | ||||
| 24.5-28.4 m/s | |||||
| 11 | Violent storm | 103-117 km/h | 11.5-16 m | Exceptionally high waves. Very large patches of foam, driven before the wind, cover much of the sea surface. Very large amounts of airborne spray severely reduce visibility. | Widespread damage to vegetation. Many roofing surfaces are damaged; asphalt tiles that have curled up and/or fractured due to age may break away completely. |
| 64-72 mph | |||||
| 56-63 kn | 37-52 ft | ||||
| 28.5-32.6 m/s | |||||
| 12 | Hurricane-force | >= 118 km/h | >= 14 m | Huge waves. Sea is completely white with foam and spray. Air is filled with driving spray, greatly reducing visibility. | Very widespread damage to vegetation. Some windows may break; mobile homes and poorly constructed sheds and barns are damaged. Debris may be hurled about. |
| >= 73 mph | |||||
| >= 64 kn | >= 46 ft | ||||
| >= 32.7 m/s |
