Beaufort number
< 1 km/h
< 1 mph
< 1 knots
< 0.3 m/s
1.1–5.5 km/h
1–3 mph
1–3 knots
0.3–1.5 m/s
5.6–11 km/h
4–7 mph
4–6 knots
1.6–3.4 m/s
12–19 km/h
8–12 mph
7–10 knots
3.5–5.4 m/s
20–28 km/h
13–17 mph
11–16 knots
5.5–7.9 m/s
29–38 km/h
18–24 mph
17–21 knots
8.0–10.7 m/s
39–49 km/h
25–30 mph
22–27 knots
10.8–13.8 m/s
50–61 km/h
31–38 mph
28–33 knots
13.9–17.1 m/s
62–74 km/h
39–46 mph
34–40 knots
17.2–20.7 m/s
75–88 km/h
47–54 mph
41–47 knots
20.8–24.4 m/s
89–102 km/h
55–63 mph
48–55 knots
24.5–28.4 m/s
103–117 km/h
64–73 mph
56–63 knots
28.5–32.6 m/s
≥ 118 km/h
≥ 74 mph
≥ 64 knots
≥ 32.7m/s
Wind speed
Calm
Light air
Smoke drift indicates wind direction.
Leaves and wind vanes are stationary.
Wind felt on exposed skin. Leaves
rustle. Wind vanes begin to move.
Leaves and small twigs constantly
moving, light flags extended.
Dust and loose paper raised. Small
branches begin to move.
Branches of a moderate size move.
Small trees in leaf begin to sway.
Large branches in motion. Whistling heard
in overhead wires. Umbrella use becomes
difficult. Empty plastic bins tip over.
Whole trees in motion. Effort needed
to walk against the wind.
Some twigs broken from trees. Cars
veer on road. Progress on foot is
seriously impeded.
Some branches break off trees, and
some small trees blow over. Construction
/temporary signs and barricades blow over.
Trees are broken off or uprooted, structural
damage likely.
Widespread vegetation and structural
damage likely.
Severe widespread damage to vegetation
and structures. Debris and unsecured
objects are hurled about.
Description
Calm. Smoke rises vertically.
Land conditions
Light breeze
Gentle breeze
Moderate breeze
Fresh breeze
Strong breeze
High wind
Gale
Strong gale
Storm
Violent storm
Hurricane force
9
BEAUFORT SCALE
Beaufort scale is an international scale of wind velocities from 0 (calm) to 12 (Hurricane force).
11
