The Beaufort Wind Scale

The Beaufort Wind Scale was originally devised by Sir Francis Beaufort to describe wind speed in chart form. By watching the effect wind has on objects in the outdoors, it is possible to estimate its speed.

#

Title

Wind Effect

MPH

0

Calm

Smoke rises vertically

Less than 1

1

Light Air

Smoke drifts

1 - 3

2

Light Breeze

Leaves rustle

4 - 7

3

Gentle Breeze

Flags fly

8 - 12

4

Moderate Breeze

Dust, loose paper raised

13 - 18

5

Fresh Breeze

Small trees sway

19 - 24

6

Strong Breeze

Difficult to use umbrellas

25 - 31

7

Moderate Gale

Difficult to walk

32 - 38

8

Fresh Gale

Twigs break off trees

39 - 46

9

Strong Gale

Slight damage to roofs

47 - 54

10

Whole Gale

Trees uprooted

55 - 63

11

Storm

Widespread damage

64 - 75

12

Hurricane

Devastation

Above 75