Beaufort Description |
Beaufort Force |
Wind Speed |
Effect on land |
| Calm
|
0
|
0-2
|
Smoke rises vertically. |
| Light Air
|
1
|
2-5
|
Smoke drifts slowly downwind. |
| Light Breeze
|
2
|
6-11
|
Wind felt on face. Leaves rustle. |
| Gentle Breeze
|
3
|
12-18
|
Leaves and small twigs in constant motion. Wind extends light flag. |
| Moderate Breeze
|
4
|
19-30
|
Raises dust and loose paper. Small branches
on trees move. |
| Fresh Breeze
|
5
|
31-39
|
Small trees in leaf begin to sway. |
| Strong Breeze
|
6
|
40-50
|
Large
branches sway. Whistling heard in overhead wires. Umbrellas used with difficulty. |
| Near Gale
|
7
|
51-61
|
Whole trees
in motion. Extra effort needed when walking against wind. |
| Gale
|
8
|
62-74
|
Twigs and small branches break off trees. Very difficult walking into wind. |
| Strong Gale
|
9
|
75-87
|
Large branches break off trees;
slight structural damage. |
| Storm
|
10
|
88-102
|
Trees uprooted; some structural damage to buildings. |
| Violent Storm
|
11
|
103-117
|
Widespread damage. |
| Hurricane
|
12
|
108-132
|
Much destruction to trees and buildings. |