Beaufort Scale
Description
0
Calm
1
Light air
2
Light breeze
3
Gentle breeze
Moderate
4
breeze
5
Fresh breeze
6
Strong breeze
7
High wind
8
Gale
9
Strong gale
10
Storm
11
Violent storm
12
Hurricane force
Wind Speed
< 1 km/h
< 1 mph
Calm. Smoke rises vertically.
< 1 knots
< 0.3 m/s
1.1 ~ 5km/h
1 ~ 3 mph
Smoke drift indicates wind direction.
1 ~ 3 knots
Leaves and wind vanes are stationary.
0.3 ~ 1.5 m/s
6 ~ 11 km/h
4 ~ 7 mph
Wind felt on exposed skin. Leaves rustle.
4 ~ 6 knots
Wind vanes begin to move.
1.6 ~ 3.3 m/s
12 ~ 19 km/h
8 ~ 12 mph
Leaves and small twigs constantly moving,
light flags extended.
7 ~ 10 knots
3.4 ~ 5.4 m/s
20 ~ 28 km/h
13 ~ 17 mph
Dust and loose paper raised. Small
11 ~ 16 knots
branches begin to move.
5.5 ~ 7.9 m/s
29 ~ 38 km/h
18 ~ 24 mph
Branches of a moderate size move.
17 ~ 21 knots
Small trees in leaf begin to sway.
8.0 ~ 10.7 m/s
39 ~ 49 km/h
Large branches in motion. Whistling heard
25 ~ 30 mph
in overhead wires. Umbrella use becomes
22 ~ 27 knots
difficult. Empty plastic bins tip over.
10.8 ~ 13.8 m/s
50 ~ 61 km/h
31 ~ 38 mph
Whole trees in motion. Effort needed to
28 ~ 33 knots
walk against the wind.
13.9 ~ 17.1 m/s
62 ~ 74 km/h
Some twigs broken from trees.
39 ~ 46 mph
Cars veer on road. Progress on foot is
34 ~ 40 knots
seriously impeded
17.2 ~ 20.7 m/s
75 ~ 88 km/h
Some branches break off trees, and some
47 ~ 54 mph
small trees blow over. Construction /
41 ~ 47 knots
temporary signs and barricades blow over.
20.8 ~ 24.4 m/s
89 ~ 102 km/h
55 ~ 63 mph
Trees are broken off or uprooted,
48 ~ 55 knots
structural damage likely.
24.5 ~ 28.4 m/s
103 ~ 117 km/h
64 ~ 73 mph
Widespread vegetation and structural
56 ~ 63 knots
damage likely.
28.5 ~ 32.6 m/s
≥ 118 km/h
Severe widespread damage to vegetation
≥ 74 mph
and structures. Debris and unsecured
≥ 64 knots
objects are hurled about.
≥ 32.7m/s
22
Land Condition