Wind strength categorization in Taiwan

Wind strength categorization in Taiwan

Wind levelNameObservable characteristics on landMeters per secondMiles per hourKnots (nautical mile per hour)
0 Calm Smoke rises vertically. 0.0-0.2 <1 <1
1 Light air Smoke drifts in the direction of the wind, but wind is not strong enough to turn wind vanes. 0.3-1.5 1-3 1-3
2 Slight, breeze Wind vanes turn in the wind. Wind is felt on the face. Leaves rustle.

1.6-3.3

4-7 4-6
3 Gentle, breeze Flags are extended slightly. Leaves and small twigs move constantly. 3.4-5.4 8-12 7-10
4 Moderate, breeze Dust and loose papers are lifted. Small tree branches move. 5.5-7.9 13-18 11-16
5 Fresh breeze Small trees in leaf begin to sway. Waves are present on the sea surface. 8.0-10.7 19-24 17-21
6 Strong, breeze Larger tree branches move. Whistling sounds in overhead electric wires. Holding an umbrella is difficult. 10.8-13.8 25-31 22-27
7 Near gale Whole trees move. Walking against the wind is difficult. 13.9-17.1 32-38 28-33
8 Gale Twigs break off trees. There is significant resistance to walking against the wind. 17.2-20.7 39-46 34-40
9 Strong gale Slight structural damage to small houses and chimney tops. 20.8-24.4 47-54 41-47
10 Storm Trees are uprooted. Houses are toppled. 24.5-28.4 55-63 48-50
11 Violent storm Wind damage that may be extensive. 28.5-32.4 64-72 57-63
12 Hurricane or Typhoon Severe catastrophe, wind wreaks widespread damage. 32.5-36.9 73-82 64-71
13 Hurricane or Typhoon Severe catastrophe, wind wreaks widespread damage. 37.0-41.4 83-92 72-80
14 Hurricane or Typhoon Severe catastrophe, wind wreaks widespread damage. 41.5-46.1 93-103 81-89
15 Hurricane or Typhoon Severe catastrophe, wind wreaks widespread damage. 46.2-50.9 104-114 90-99
16 Hurricane or Typhoon Severe catastrophe, wind wreaks widespread damage. 51.0-56.0 115-125 100-108
17 Hurricane or Typhoon Severe catastrophe, wind wreaks widespread damage. 56.1-61.2 126-136 109-118

Note : Marine and land standard indicators are both expressed as levels between 0 and 17,
with wind speed units in m/sec or kts/hr.
1 m/sec = 1.9 kts/hr ( = 3.6 km/hr).