The Beaufort wind scale was defined in 1805 by Admiral Frances Beaufort to describe the wind effects on a fully rigged Man of War Frigate. Over the years the scale has been adapted to show the effects on land as well which is shown below.
Originally to allow for estimation of wind speed without an instrument it’s now used as a basic scale to indicate the wind.
| Beaufort Wind Scale | ||||
|---|---|---|---|---|
| Beaufort Force Number | Mean Wind Speed (mph) | Limits (MPH) | Description | Effects |
| 0 | 0 | 0 | Calm | Smoke Rises Vertically |
| 1 | 2 | 1 - 3 | Light Air | Smoke Drift Indicating Direction |
| 2 | 5 | 4 - 7 | Light Breeze | Wind Felt on Face, Leaves Rustle |
| 3 | 10 | 8 - 12 | Gentle Breeze | Leaves, Small Twigs in constant motion |
| 4 | 15 | 13 - 18 | Moderate Breeze | Dust and Leaves raised up, Branches move |
| 5 | 21 | 19 - 24 | Fresh Breeze | Small Trees begin to sway |
| 6 | 28 | 24 - 31 | Strong Breeze | Large Branches of Trees in motion |
| 7 | 35 | 32 - 38 | Moderate Gale | Whole Trees in motion, resistance felt to walking against the wind |
| 8 | 42 | 39 - 46 | Fresh Gale | Twigs and small branches break from Trees |
| 9 | 50 | 47 - 54 | Strong Gale | Large Branches break from Trees |
| 10 | 59 | 55 - 63 | Whole Gale | Trees broken and uprooted |
| 11 | 68 | 64 - 72 | Storm | Widespread Damage |
| 12 | 78 | 73 - 82 | Hurricane | Violence and Destruction |
| 13 | 88 | 83 - 92 | ||