| FORCE | EQUIVALENT | SPEED | DESCRIPTION | SPECIFICATIONS FOR USE ON LAND |
| 10 m above ground | miles/hour knots | |||
| 0 | 0-1 | 0-1 | Calm | Calm; smoke rises verticall. |
| 1 | 1-3 | 1-3 | Light air | Direction of wind shown by smoke drift, but not by wind vanes. |
| 2 | 4-7 | 4-6 | Light Breeze | Wind felt on face; leaves rustle; ordinary vanes moved by wind. |
| 3 | 8-12 | 7-10 | Gentle Breeze | Leaves and small twigs in constant motion; wind extends light flag. |
| 4 | 13-18 | 11-16 | Moderate Breeze | Raises dust and loose paper; small branches are moved. |
| 5 | 19-24 | 17-21 | Fresh Breeze | Small trees in leaf begin to sway; crested wavelets form on inland waters. |
| 6 | 25-31 | 22-27 | Strong Breeze | Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty. |
| 7 | 32-38 | 28-33 | Near Gale | Whole trees in motion; inconvenience felt when walking against the wind. |
| 8 | 39-46 | 34-40 | Gale | Breaks twigs off trees; generally impedes progress. |
| 9 | 47-54 | 41-47 | Severe Gale | Slight structural damage occurs (chimney-pots and slates removed). |
| 10 | 55-63 | 48-55 | Storm | Seldom experienced inland; trees uprooted; considerable structural damage occurs. |
| 11 | 64-72 | 56-63 | Violent Storm | Very rarely experienced; accompanied by wide-spread damage. |
| 12 | 73-83 | 64-71 | Hurricane -- | see Saffir/Simpson Hurricane Scale |
Updated: Saturday, October 4, 2014 8:59