How to Measure Wind Speed: The Beaufort Wind Force Scale

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Coconut palms tree during heavy wind or hurricane. Rainy day
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Estimate the Wind Speed with Your Eyes

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Did you know you can measure wind speed with your EYES? The Beaufort Wind Force Scale, devised in the early 19th century by British naval officer Sir Francis Beaufort, remains a crucial tool for sailors and meteorologists alike. This scale quantifies wind intensity based on observed sea conditions, offering a standardized measure of wind strength. 

From calm (Force 0) to hurricane force (Force 12), each level describes the wind’s effects on the sea’s surface, from ripples to towering waves. Initially, it helped sailors estimate wind speeds by observing the state of the sea, ensuring safer navigation. Despite modern technology, the Beaufort Scale is a valuable reference, aiding mariners, aviators, and weather enthusiasts in understanding and predicting wind behavior, enriching our grasp of atmospheric dynamics.

Here’s a wind force scale adapted to land use so that you can estimate the wind speed wherever you are.

“Used Mostly at Sea but of Help to All Who Are Interested in the Weather”

Wind Force Scale

Beaufort ForceDescriptionWhen You See or Feel This EffectWind (mph)Wind (km/h)
0CalmSmoke goes straight upless than 1less than 2
1Light airWind direction is shown by smoke drift but not by wind vane1-32-5
2Light breezeWind is felt on the face; leaves rustle; wind vanes move4-76-11
3Gentle breezeLeaves and small twigs move steadily; wind extends small flags straight out8-1212-19
4Moderate breezeWind raises dust and loose paper; small branches move13-1820-29
5Fresh breezeSmall trees sway; waves form on lakes19-2430-39
6Strong breezeLarge branches move; wires whistle; umbrellas are difficult to use25-3140-50
7Near galeWhole trees are in motion; walking against the wind is difficult32-3851-61
8GaleTwigs break from trees; walking against the wind is very difficult39-4662-74
9Strong galeBuildings suffer minimal damage; roof shingles are removed47-5475-87
10Whole gale (Storm)Trees are uprooted55-6388-101
11Violent stormWidespread damage64-72102-116
12HurricaneWidespread destruction73+117+
About The Author

Catherine Boeckmann

Catherine Boeckmann loves nature, stargazing, and gardening so it’s not surprising that she and The Old Farmer’s Almanac found each other. She leads digital content for the Almanac website, and is also a certified master gardener in the state of Indiana. Read More from Catherine Boeckmann

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