Beaufort Scale

Description

MPH

Scale

KM

Scale

0

calm

smoke rises vertically

0

-

1

0

-

2

1

light air

smoke drifts slowly

2

-

3

3

-

5

2

slight breeze

leaves rustle; wind vane moves

4

-

7

7

-

11

3

gentle breeze

twigs move, flags extended

8

-

12

13

-

20

4

moderate breeze

branches move; dust and paper rise

13

-

18

21

-

30

5

fresh breeze

small trees sway

19

-

24

31

-

39

6

strong breeze

large branches sway; whires whislte

25

-

31

41

-

51

7

moderate gale

trees in motion; walking difficult

32

-

38

52

-

62

8

fresh gale

twigs break off trees

39

-

46

64

-

75

9

strong gale

branches break; roofs damaged

47

-

54

77

-

89

10

whole gale

trees snap; damage evident

55

-

63

90

-

103

11

storm

widespread damage

64

-

72

105

-

118

12

hurricane

extreme damage

73

-

82

120

-

134