| Beaufort Number | Wind speed | Description | Wave Height | Sea Conditions | Land Conditions |
| kt | km/h | mph | m/s | m/ft |
| 0 | 0 | 0 | 0 | 0-0.2 | Calm | 0/0 | Flat | Calm, smoke rises vertically |
| 1 | 1-3 | 1-6 | 1-3 | 0.3-1.5 | Light Air | 0.1/0.33 | Ripples without crests | Wind motion visible in smoke |
| 2 | 4-6 | 7-11 | 4-7 | 1.6-3.3 | Light
Breeze | 0.2/0.66 | Small wavelets, crests of glassy appearance, not breaking | Wind felt on exposed skin, leaves rustle |
| 3 | 7-10 | 12-19 | 8-12 | 3.4-5.4 | Gentle
Breeze | 0.6/2 | Large wavelets, crests begin to break, scattered whitecaps | Leaves and smaller twigs in constant motion |
| 4 | 11-16 | 20-29 | 13-18 | 5.5-7.9 | Moderate
Breeze | 1/3.3 | Small waves | Dust and loose paper raised. Small branches begin to move. |
| 5 | 17-21 | 30-39 | 19-24 | 8.0-10.7 | Fresh
Breeze | 2/6.6 | Moderate (1.2 m) longer waves, some foam and spray | Smaller trees sway |
| 6 | 22-27 | 40-50 | 25-31 | 10.8-13.8 | Strong
Breeze | 3/9.9 | Large waves with foam crests and some spray | Large branches in motion, whistling heard in overhead wires, umbrella use becomes difficult |
| 7 | 28-33 | 51-62 | 32-38 | 13.9-17.1 | Near
Gale | 4/13.1 | Sea heaps up and foam begins to streak | Whole trees in motion, effort needed to walk against the wind |
| 8 | 34-40 | 63-75 | 39-46 | 17.2-20.7 | Gale | 5.5/18 | Moderately high waves with breaking crests forming spindrift, streaks of foam | Twigs broken from trees, cars veer on road |
| 9 | 41-47 | 76-87 | 47-54 | 20.8-24.4 | Strong
Gale | 7/23 | High waves (2.75 m) with dense foam, wave crests start to roll over, considerable spray | Light structure damage |
| 10 | 48-55 | 88-102 | 55-63 | 24.5-28.4 | Storm | 9/29.5 | Very high waves, sea surface is white with considerable tumbling, visibility reduced | Trees uprooted. Considerable structural damage |
| 11 | 56-63 | 103-117 | 64-72 | 28.5-32.6 | Violent
Storm | 11.5/37.7 | Exceptionally high waves | Widespread structural damage |
| 12 | >63 | >117 | >72 | >32.7 | Hurricane | 14+/46+ | Huge waves, air filled with foam and spray, sea completely white with driving spray, visibility very greatly reduced | Massive and widespread damage to structures |
Kirt
