Winds on the Beaufort scale
| Wind | Designation | From Winds | Effect | |||
|---|---|---|---|---|---|---|
| km/h | m/s | Knots | mph | |||
| 0 | Calm | < 1 | < 0,3 | < 1 | < 1 | Nothing |
| 1 | Light air | 1 - 5 | 0,3 - 1,5 | 1 - 3 | 1 - 3 | Diversion of smoke |
| 2 | Light breeze | 6 - 11 | 1,6 - 3,3 | 4 - 6 | 4 - 7 | Contractions of leaves |
| 3 | Gentle breeze | 12 - 19 | 3,4 - 5,4 | 7 - 10 | 8 - 12 | Movement of branches |
| 4 | Moderate breeze | 20 - 28 | 5,5 - 7,9 | 11 - 15 | 13 - 17 | Movement of limbs |
| 5 | Fresh breeze | 29 - 38 | 8,0 - 10,7 | 16 - 21 | 18 - 24 | Movement of small trees |
| 6 | Strong breeze | 39 - 49 | 10,8 - 13,8 | 22 - 27 | 25 - 30 | Movement strong branches |
| 7 | High wind | 50 - 61 | 13,9 - 17,1 | 28 - 33 | 31 - 38 | Movement of trees |
| 8 | Gale | 62 - 74 | 17,2 - 20,7 | 34 - 40 | 39 - 46 | Difficulty in walking |
| 9 | String gale | 75 - 88 | 20,8 - 24,4 | 41 - 47 | 47 - 54 | House damage |
| 10 | Storm | 89 - 102 | 24,5 - 28,4 | 48 - 55 | 55 - 63 | Uprooting of trees |
| 11 | Violent storm | 103 - 117 | 28,5 - 32,6 | 56 - 63 | 64 - 73 | Storm damage |
| 12 | Hurricane | > 118 | > 32,7 | > 64 | > 74 | Devastation |
What is the Beaufort Scale?
The Beaufort scale is the most common scale for classifying and naming winds according to their speed.
The scale was named after Sir Francis Beaufort (1774 - 1857). However, the man did not contribute much to the development of the scale.
If a wind force is mentioned without the addition of a special scale, it is usually related to the Beaufort scale. Thus, information on wind speeds in weather forecasts or in logbooks usually refers to the Beaufort Scale as well.
How does the Beaufort Scale work?
The current version of the scale was defined in 1970 with 13 wind speeds. There are 13 classifications in total, ranging from wind force 0 to 12. Based on the wind speed the wind force can be classified in the Beaufort Scale. Thereby the speeds in the Beaufort Scale are divided into ranges. In the table you will find the ranges in km/h, m/s, knots and mph. The speed is measured 10 meters above the ground.
The last stage (12) begins at 119 kilometres per hour (km/h). This corresponds to 64 knots, 32.7 m/s or even 74 mph. The last stage in the Beaufort Scale is called a hurricane and is described with devastation. Level 0 of the Beaufort Scale describes calm and refers to wind speeds of less than 1 kilometre per hour (km/h).
The steps of the Beaufort Scale are relatively linear to the wind speeds.
For each scale classification there is a description of the effect on nature. In the table you will find the effects on the land. Primarily in relation to the effects on trees.
Beaufort scale with 18 wind speeds
In 1949 the scale was extended by 5 wind forces. So for a while there were 18 wind forces. In this scale the wind force 17 was the highest. However, this variant is no longer used. So you can find the current version of the Beaufort scale in the table before.