How to Measure Wind Speed: The Beaufort Wind Force Scale
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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 Force | Description | When You See or Feel This Effect | Wind (mph) | Wind (km/h) |
| 0 | Calm | Smoke goes straight up | less than 1 | less than 2 |
| 1 | Light air | Wind direction is shown by smoke drift but not by wind vane | 1-3 | 2-5 |
| 2 | Light breeze | Wind is felt on the face; leaves rustle; wind vanes move | 4-7 | 6-11 |
| 3 | Gentle breeze | Leaves and small twigs move steadily; wind extends small flags straight out | 8-12 | 12-19 |
| 4 | Moderate breeze | Wind raises dust and loose paper; small branches move | 13-18 | 20-29 |
| 5 | Fresh breeze | Small trees sway; waves form on lakes | 19-24 | 30-39 |
| 6 | Strong breeze | Large branches move; wires whistle; umbrellas are difficult to use | 25-31 | 40-50 |
| 7 | Near gale | Whole trees are in motion; walking against the wind is difficult | 32-38 | 51-61 |
| 8 | Gale | Twigs break from trees; walking against the wind is very difficult | 39-46 | 62-74 |
| 9 | Strong gale | Buildings suffer minimal damage; roof shingles are removed | 47-54 | 75-87 |
| 10 | Whole gale (Storm) | Trees are uprooted | 55-63 | 88-101 |
| 11 | Violent storm | Widespread damage | 64-72 | 102-116 |
| 12 | Hurricane | Widespread destruction | 73+ | 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.
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