Beaufort Scale

0

Calm

Sea like mirror

Smoke rises vertically

<1

<1

<1

1

Very Light

Ripples with appearance of scales, no form crests

Direction of wind shown by smoke drift but not by wind vanes

1 – 3

1 – 5

1 – 3

2

Light breeze

Wavelets, small but pronounced. Crests with glassy appearance, but do not break

Wind felt on face, leaves rustle, ordinary wind vane moved by wind

4 – 6

6 – 11

4 – 7

3

Gentle breeze

Large wavelets, crests begin to break. Glassy looking foam, occasional white horses

Leaves and small twigs in constant motion, wind extends light flag

7 – 10

12 – 19

8 – 12

4

Moderate breeze

Small waves becoming longer, frequent white horses

Wind raises dust and loose paper, small branches move

11 – 16

20 – 29

13 – 18

5

Fresh breeze

Moderate waves of pronounced long form. Many white horses, some spray

Small trees in leaf start to sway crested wavelets form on inland waters.

17 – 21

30 – 39

19 – 24

6

Strong breeze

Some large waves, extensive white foam crests, some spray

Large branches in motion, whistling in telegraph wires, umbrellas used with difficulty

22 – 27

40 – 50

25 – 31

7

Near gale

Sea heaped up, white foam from breaking waves blowing in streaks with the wind.

Whole trees in motion, inconvenience felt when walking against wind

28 – 33

51 – 61

32 – 38

8

Gale

Moderately high and long waves. Crests break into spindrift, blowing foam in well marked streaks

Twigs break from trees, difficult to walk

34 – 40

62 – 74

39 – 46

9

Strong gale

High waves, dense foam streaks in wind, wave crests topple, tumble and roll over. Spray reduces visibility

Slight structural damage occurs, chimney pots and slates removed

41 – 47

75 -87

47 – 54

10

Storm

Very 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 – 55

88 – 101

55 – 63

11

Violent storm

Exceptionally 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 visibility

Widespread damage

56 – 63

102 – 117

64 – 73

12

Hurricane

Air filled with foam and spray, sea white with driving spray, poor visibility

Widespread damage

>64

>119

>74