Description

Wind Speed
Knots

Wind Speed
Km

Force

Land

Water

Calm

0 - 1

0 1

0

Smoke rises
vertically

Water is like a mirror. Cannot sail.

Light Air

1 - 3

1 - 5

1

Smoke indicates direction. Not enough wind for  vanes

Small ripples on water. Enough  wind for a light Spinnaker

Light Breeze

4 - 6

6 - 11

2

Wind felt on face. Tree leaves start moving. Vanes now indicate direction.

Small wavelets. Wind now fills sail.

Gentle Breeze

7 - 10

12 - 19

3

Small flags are extended. Leaves move constantly.

Large wavelets. Sailboats start to heel.

Moderate Breeze

11 - 16

20 - 28

4

Dust is raised by wind. Small branches start bending.

Good working breeze. Saiboats at hull speed, full  sail.

Fresh Breeze

17 - 21

29 - 38

5

Small trees are reacting to wind.

Numerous whitecaps. Time to shorten sails.

Strong Breeze

22 - 27

39 - 49

6

Wind now whistles. Most branches in trees moving.

Whitecaps eveywhere. Sailboats start to head ashore.

Near Gale

28 ­ 33

50 - 61

7

Whole trees now move.

Much bigger waves. Sailboats remain at harbour.

Gale

34 - 40

62 - 74

8

Small branches are starting to break. Walking is now hard.

Foam in well marked streaks. All boats now head in.

Strong Gale

41 - 47

75 - 88

9

Buildings are starting to show small damage.

Low visibility due to spray.

Storm

48 - 55

89 - 102

10

Dangerous Situation

High seas over 8 metres

Violent Storm

56 - 63

103 - 117

11

Dangerous situation

High seas over 10 metres

Hurricane

Over 63

Over 117

12

Dangerous situation

High seas over 14 metres