The Beaufort Wind Scale

This is one way that the strength of the wind is measured. The scale is named after Sir Francis Beaufort, who developed it in 1805 for use by sailors. You can use the Beaufort scale to measure the force of the wind by looking at the effects of the wind on things around you.

Beaufort Scale Description What you'll see on land
Force 0 Calm
0 km per hour
Smoke rises vertically
Force 1 Light air
1-5 km per hour
Smoke blown by wind
Force 2 Light breeze
6-11 km per hour
Leaves rustle, you feel the wind on your face
Force 3 Gentle breeze
12-19 km per hour
Leaves and twigs on trees moving constantly. Flags flutter
Force 4 Moderate breeze
20-30 km per hour
Wind raise dust and fallen leaves. Paper blows around. Small tree branches sway
Force 5 Fresh breeze
31-39 km per hour
Small trees begin to sway
Force 6 Strong breeze
40-50 km per hour
Large branches sway. Umbrellas hard to hold, blown inside out
Force 7 Near gale
51-61 km per hour
Whole trees sway. You can feel the wind pushing you
Force 8 Gale
62-74 km per hour
Difficult to walk in the wind. Twigs broken off trees
Force 9 Strong gale
75-87 km per hour
Tiles blown off roofs, tree branches blown down
Force 10 Storm
88-102 km per hour
Damage to houses. Whole trees broken or blown over
Force 11 Violent storm
102-116 km per hour
Serious damage
Force 12 Cyclone
117-132 km per hour
Widespread damage

Go here to see some drawings of the effects of the wind as measured by the Beaufort Scale

Thomas, Ron. & Sydenham, S. The Beaufort wind scale [Online] (2009)

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updated  March 2009 © kidcyber