|
The Beaufort Scale for use on land |
|
Beaufort Force
|
Description
|
Effects on land
|
Speed
|
|
knots |
km/h |
mph |
|
0 |
Calm |
Smoke rises vertically.
|
Less than 1 |
Less than 1 |
Less than 1 |
|
1 |
Light Air |
Direction of wind shown by smoke drift, but not by wind vanes. |
1 - 3 |
1 - 5 |
1 - 3 |
|
2 |
Light breeze |
Wind felt on face; leaves rustle; ordinary vanes moved by wind.
|
4 -6 |
6 - 11 |
4 -7 |
|
3 |
Gentle breeze |
Leaves and small twigs in constant motion; wind extends light flag.
|
7 - 10 |
12 - 19 |
8 - 12 |
|
4 |
Moderate breeze |
Raises dust and loose paper; small branches are moved.
|
11 - 16 |
20 - 29 |
13 - 18 |
|
5 |
Fresh breeze |
Small trees in leaf begin to sway; crested wavelets form on inland waters.
|
17 - 21 |
30 - 39 |
19 - 24 |
|
6 |
Strong breeze |
Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty.
|
22 - 27 |
40 - 50 |
25 - 31 |
|
7 |
Near gale |
Whole trees in motion; inconvenience felt when walking against the wind.
|
28 - 33 |
51 - 61 |
32 - 38 |
|
8 |
Gale |
Breaks twigs off trees; generally impedes progress.
|
34 - 40 |
62 - 74 |
39 - 46 |
|
9 |
Strong gale |
Slight structural damage occurs (chimney-pots and slates removed).
|
41 - 47 |
75 - 87 |
47 - 54 |
|
10 |
Storm |
Seldom experienced inland; trees uprooted; considerable structural damage occurs.
|
48 - 55 |
88 - 101 |
55 - 63 |
|
11 |
Violent storm |
Very rarely experienced; accompanied by wide-spread damage.
|
56 - 63 |
102 - 117 |
64 - 73 |
|
12 |
Hurricane |
Whole hangars disappear. |
>64 |
>119 |
>74 |
