How to Measure Wind Speed Beaufort Wind Force Scale

Coconut palms tree during heavy wind or hurricane. Rainy day

Photo Credit

tuaindeed/Shutterstock

Estimate the Wind Speed with Your Eyes

Written By: Catherine Boeckmann Executive Digital Editor and Master Gardener

October 23, 2023

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.

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+

Weather References

About The Author

Catherine Boeckmann

Executive Digital Editor and Master Gardener

Catherine Boeckmann is the Executive Digital Editor of Almanac.com, the website companion of The Old Farmer's Almanac. She covers gardening, plants, pest control, soil composition, seasonal and moon c...