Wind strength categorization in Taiwan
Wind level | Name | Observable characteristics on land | Meters per second | Miles per hour | Knots (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).