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