| No. | Description | Features | Speed (mph) |
| 0 | Calm | Smoke rises vertically; water smooth | 0–1 |
| 1 | Light Air | Smoke shows wind direction; water ruffled | 1–3 |
| 2 | Light Breeze | Leaves rustle; wind felt on face | 4–7 |
| 3 | Gentle Breeze | Loose paper blows around | 8–12 |
| 4 | Moderate Breeze | Branches sway | 13–18 |
| 5 | Fresh Breeze | Small trees sway, leaves blown off | 19–24 |
| 6 | Strong Breeze | Whistling in telephone wires; sea spray from waves | 25-31 |
| 7 | Near Gale | Large trees sway | 32–38 |
| 8 | Gale | Twigs break from trees | 39–46 |
| 9 | Strong Gale | Branches break from trees | 47–54 |
| 10 | Storm | Trees uprooted; weak buildings collapse | 55–63 |
| 11 | Violent Storm | Widespread damage | 64–73 |
| 12 | Hurricane | Widespread structural damage | above 74 |