Beaufort Wind Scale (2024)

Force Wind
(Knots) WMO
Classification Appearance of Wind EffectsOn the Water On Land 0 Less than 1 Calm Sea surface smooth and mirror-like Calm, smoke rises vertically1 1-3 Light Air Scaly ripples, no foam crests Smoke drift indicates wind direction, still wind vanes 2 4-6 Light Breeze Small wavelets, crests glassy, no breaking Wind felt on face, leaves rustle, vanes begin to move 3 7-10 Gentle Breeze Large wavelets, crests begin to break, scattered whitecaps Leaves and small twigs constantly moving, light flags extended 4 11-16 Moderate Breeze Small waves 1-4 ft. becoming longer, numerous whitecaps Dust, leaves, and loose paper lifted, small tree branches move5 17-21 Fresh Breeze Moderate waves 4-8 ft taking longer form, many whitecaps, some spray Small trees in leaf begin to sway6 22-27 Strong Breeze Larger waves 8-13 ft, whitecaps common, more spray Larger tree branches moving, whistling in wires7 28-33 Near Gale Sea heaps up, waves 13-19 ft, white foam streaks off breakers Whole trees moving, resistance felt walking against wind8 34-40 Gale Moderately high (18-25 ft) waves of greater length, edges of crests begin to break into spindrift, foam blown in streaks Twigs breaking off trees, generally impedes progress9 41-47 Strong Gale High waves (23-32 ft), sea begins to roll, dense streaks of foam, spray may reduce visibility Slight structural damage occurs, slate blows off roofs10 48-55 Storm Very high waves (29-41 ft) with overhanging crests, sea white with densely blown foam, heavy rolling, lowered visibility Seldom experienced on land, trees broken or uprooted, "considerable structural damage"11 56-63 Violent Storm Exceptionally high (37-52 ft) waves, foam patches cover sea, visibility more reduced &nbsp12 64+ Hurricane Air filled with foam, waves over 45 ft, sea completely white with driving spray, visibility greatly reduced &nbsp