The Beaufort Scale

windy day

Have you ever wondered how to tell what the wind speed is? Below is a useful scale that you can use simply through your observations. This can be really handy if you are trying to keep track of the weather on a regular basis. In Kamana 3.4 and 3.5 you record the wind speed and direction. This scale can be invaluable.

The Beaufort Scale can be used to help estimate the wind speed without any fancy equipment. A British Navy Admiral named Sir Francis Beaufort developed it in 1806. Sir Francis took the work of many others and standardized it. The original scale describes ocean conditions, not vegetation, to estimate the wind. Use this scale for your own weather observations and predictions!

Beaufort Number Wind Speed Description Observations
0 Under 1 mph (under 1 knot) Calm Smoke rises straight up
1 1-3 mph               (1-3 knots) Light Breeze Drift of smoke shows wind direction, wind vanes are still
2 4-7 mph

(4-6 knots)

Slight Breeze Leaves rustle; wind felt on face
3 8-12 mph

(7-10 knots)

Gentle Breeze Leaves & twigs in constant motion
4 13-18 mph

(11-16 knots)

Moderate Breeze Small branches move; dust & loose paper are moved
5 19-24 mpg

(17-21 knots)

Fresh Breeze Small Trees Sway
6 25-31 mph

(22-27 knots)

Strong Breeze Large branches move
7 32-38 mph

(28-33 knots)

Moderate Gale Whole trees sway
8 39-46 mph

(34-40 mph)

Fresh Gale Twigs snap off trees
9 47-54 mph

(41-47 knots)

Strong Gale Branches break; slight damage to buildings
10 55-63 mph

(48-55 knots)

Whole Gale Trees uprooted; moderate building damage
11 64-72 mph

(56-63 knots)

Storm Widespread damage
12 73 mph & over

(64+ knots)

Hurricane Force Extreme damage
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