Wind Force

Beaufort Scale of Wind Force

ScaleForce RatingObservable Land EffectsSpeed MPHEffect at sea
0Calm Vertical Smoke 1 Calm (Glassy)
1Light Air Slight smoke drift 1-3 Calm (Rippled)
2Light Breeze Leaves gently rustle 4-7 Smooth (wavelets)
3Gentle Breeze Leaves and twigs move 8-12 Slight
4Moderate Breeze Raises paper moves small branches 13-18 Slight to Moderate
5Fresh Breeze Sways small leafy trees 19-24 Moderate
6Strong Breeze Sways large branches 25-31 Rough
7Moderate Gale Trees sway 32-38 Rough to very rough
8Fresh Gale Broken twigs, walking impeded 39-46 Very rough to high
9Strong Gale Chimneys, slates, hoardings damaged 47-54 High
10Whole Gale Trees Blown Down and Considerable damage 55-63 Very high
11Storm Major Damage 64-75 Very high
12Hurricane Very dangerous tropical whirling winds 76+ Phenomenal