| 0 | Less than 1 | Less than 1 | Calm | Sea surface like a mirror, but not necessarily flat. | Smoke rises vertically. |
| 1 | 1 - 5 | 1 - 3 | Light air | Ripples with the appearance of scales are formed, but without foam crests. | Direction of wind shown by smoke drift, but not wind vanes. |
| 2 | 6 - 11 | 4 - 6 | Light breeze | Small wavelets, still short but more pronounced. Crests do not break. When visibility good, horizon line always very clear. | Wind felt on face. Leaves rustle. Ordinary vane moved by wind. |
| 3 | 12 - 19 | 7 - 10 | Gentle breeze | Large wavelets. Crests begin to break. Foam of glassy appearance. Perhaps scattered whitecaps. | Leaves and small twigs in constant motion. Wind extends light flag. |
| 4 | 20 - 28 | 11 - 16 | Moderate breeze | Small waves, becoming longer. Fairly frequent whitecaps. | Raises dust and loose paper. Small branches are moved. |
| 5 | 29 - 38 | 17 - 21 | Fresh breeze | Moderate waves, taking a more pronounced long form. Many whitecaps are formed. Chance of some spray. | Small trees with leaves begin to sway. Crested wavelets form on inland waters. |
| 6 | 39 - 49 | 22 - 27 | Strong breeze | Large waves begin to form. The white foam crests are more extensive everywhere. Probably some spray. | Large branches in motion. Whisteling heard in telephone wires. Umbrellas used with difficulty. |
| 7 | 50 - 61 | 28 - 33 | Near gale | Sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind. | Whole trees in motion. Inconvenience felt in walking against wind. |
| 8 | 62 - 74 | 34 - 40 | Gale | Moderately high waves of greater length. Edges of crests begin to break into the spindrift. The foam is blown in well-marked streaks along the direction of the wind. | Breaks twigs off trees. Generally impedes progress. Walking into wind almost impossible. |
| 9 | 75 - 88 | 41 - 47 | Strong gale | High waves. Dense streaks of foam along the direction of the wind. Crests of waves begin to topple, tumble and roll over. Spray may affect visibility. | Slight structural damage occurs, e.g. roofing shingles may become loose or blow off. |
| 10 | 89 - 102 | 48 - 55 | Storm | Very high waves with long overhanging crests. Dense white streaks of foam. Surface of the sea takes a white appearance. The tumbling of the sea becomes heavy and shock-like. Visibility affected. | Trees uprooted. Considerable structural damage occurs. |
| 11 | 103 - 117 | 56 - 63 | Violent storm | Exceptionally high waves. Sea completely covered with long white patches of foam. Visibility affected. | Widespread damage. |
| 12 | 118 - 133 | 64 - 71 | Hurricane | Air filled with foam and spray. Sea entirely white with foam. Visibility seriously impaired. | Rare. Severe widespread damage to vegetation and significant structural damage possible. |
