0CalmSea like mirrorSmoke rises vertically<1<1<1
1Very LightRipples with appearance of scales, no form crests
Direction of wind shown by smoke drift but not by wind vanes
1 – 31 – 51 – 3
2Light breezeWavelets, small but pronounced. Crests with glassy appearance, but do not breakWind felt on face, leaves rustle, ordinary wind vane moved by wind4 – 66 – 114 – 7
3Gentle breezeLarge wavelets, crests begin to break. Glassy looking foam, occasional white horsesLeaves and small twigs in constant motion, wind extends light flag7 – 1012 – 198 – 12
4Moderate breezeSmall waves becoming longer, frequent white horsesWind raises dust and loose paper, small branches move11 – 1620 – 2913 – 18
5Fresh breezeModerate waves of pronounced long form. Many white horses, some spraySmall trees in leaf start to sway crested wavelets form on inland waters.17 – 2130 – 3919 – 24
6Strong breezeSome large waves, extensive white foam crests, some sprayLarge branches in motion, whistling in telegraph wires, umbrellas used with difficulty22 – 2740 – 5025 – 31
7Near galeSea heaped up, white foam from breaking waves blowing in streaks with the wind.Whole trees in motion, inconvenience felt when walking against wind28 – 3351 – 6132 – 38
8GaleModerately high and long waves. Crests break into spindrift, blowing foam in well marked streaksTwigs break from trees, difficult to walk34 – 4062 – 7439 – 46
9Strong galeHigh waves, dense foam streaks in wind, wave crests topple, tumble and roll over. Spray reduces visibilitySlight structural damage occurs, chimney pots and slates removed41 – 4775 -8747 – 54
10StormVery high waves with long overhanging crests. Dense blowing foam, sea surface appears white. Heavy tumbling of sea, shock-like, poor visibility.Trees uprooted, considerable structural damage occurs.48 – 5588 – 10155 – 63
11Violent stormExceptionally high waves, sometimes concealing small and medium sized ships. Sea completely covered with long white patches of foam. Edges of wave crests blown into froth. Poor visibilityWidespread damage56 – 63102 – 11764 – 73
12HurricaneAir filled with foam and spray, sea white with driving spray, poor visibilityWidespread damage>64>119>74