Beaufort Scale
(Standard height of 10 meters above the ground)
| Beaufort Force | Wind Description | The average wind speed at the height of 10 meters above the ground | Wind Effect Description | |
|---|---|---|---|---|
| wind | m/s | km/hr | Terrestrial situation | |
| 0 | calm | 0 - 0.2 | ＜1 | Smoke rises vertically. |
| 1 | light air | 0.3 - 1.5 | 1 - 5 | Smoke drift indicates wind direction, still wind vanes. |
| 2 | light breeze | 1.6 - 3.3 | 6 - 11 | Wind felt on face, leaves rustle, vanes begin to move. |
| 3 | gentle breeze | 3.4 - 5.4 | 12 - 19 | Leaves and small twigs constantly moving, light flags extended. |
| 4 | moderate breeze | 5.5 - 7.9 | 20 - 28 | Dust and loose paper lifted, small tree branches move. |
| 5 | fresh breeze | 8.0 - 10.7 | 29 - 38 | Small trees in leaf begin to sway. |
| 6 | strong breeze | 10.8 - 13.8 | 39 - 49 | Large tree branches moving, whistling in wires. Umbrella use becomes difficult. |
| 7 | near gale | 13.9 - 17.1 | 50 - 61 | Whole trees in motion, resistance felt when walking against the wind. |
| 8 | gale | 17.2 - 20.7 | 62 - 74 | Twigs broken from trees. Progress generally impedes. |
| 9 | strong gale | 20.8 - 24.4 | 75 - 88 | Slight structural damage occurs. Chimney post removed. |
| 10 | storm | 24.5 - 28.4 | 89 - 102 | Trees uprooted. Considerable structural damage. |
| 11 | violent storm | 28.5 - 32.6 | 103 - 117 | Extremely rare. Widespread damage. |
| 12 | hurricane | 32.7 - 36.9 | 118 - 133 | － |
| 13 | hurricane | 37.0 - 41.4 | 134 - 149 | － |
| 14 | hurricane | 41.5 - 46.1 | 150 - 166 | － |
| 15 | hurricane | 46.2 - 50.9 | 167 - 183 | － |
| 16 | hurricane | 51.0 - 56.0 | 184 - 201 | － |
| 17 | hurricane | 56.1 - 61.2 | 202 - 220 | － |
Source reference: ROC Central Weather Bureau