Wind force is classified according to the Beaufort Wind Scale:
| Beaufort Wind Scale | ||||
| Force | Speed (MPH) | Speed (knots) | Description | Typical Effects on Land |
| W0 | 0-1 | 0-1 | Calm | Calm; smoke rises vertically. |
| W1 | 1-3 | 1-3 | Light air | Direction of wind shown by smoke drift, but not by wind vanes. |
| W2 | 4-7 | 4-6 | Light breeze | Wind felt on face. Leaves rustle; ordinary vanes moved by wind. |
| W3 | 8-12 | 7-10 | Gentle breeze | Leaves and small twigs in constant motion; wind extends light flag. |
| W4 | 13-18 | 11-16 | Moderate breeze | Raises dust and loose paper; small branches move. |
| W5 | 19-24 | 17-21 | Fresh breeze | Small trees in leaf begin to sway; crested wavelets form on inland waters. |
| W6 | 25-31 | 22-27 | Strong breeze | Large branches in motion; whistling heard in utility wires; umbrellas used with difficulty. |
| W7 | 32-38 | 28-33 | Near gale | Whole trees in motion; inconvenience felt when walking against the wind. |
| W8 | 39-46 | 34-40 | Gale | Breaks twigs off trees; generally, impedes progress. |
| W9 | 47-54 | 41-47 | Severe gale | Slight structural damage occurs (chimney pots and roof slates removed). |
| W10 | 55-63 | 48-55 | Storm | Seldom experienced inland. Trees uprooted; considerable structural damage occurs. |
| W11 | 64-72 | 56-63 | Violent storm | Very rarely experienced; accompanied by widespread damage. |
| W12 | 73-83 | 64-71 | Hurricane | Violent destruction |