Wind speed is measured with anemometers, which spin in the wind. Wind speed can also be measured with the naked eye, a little less accurately, but completely satisfactorily for most of us with this wind detector.
To make a wind detector
- Mark the points of the compass on a paper plate with heavy ink. Write N, S, E, and W on each of the four main marks.
- From each point staple a crepe paper or wide ribbon streamer about a foot and a half long so that it hangs down from the rim of the plate.
- On the face of the plate write these Beaufort wind speed determiners:
0 = calm /smoke drifts straight up
1 = moving air / wind speed 1.8 mph / barely felt air movement.
2 = light breeze / wind speed 5.6 mph / leaves rustle
3 = medium breeze/ wind speed 9.3 mph / branches sway slightly
4 = moderate wind / wind speed 16 mph / branches are swaying
5 = fresh wind / wind speed 22 mph / small trees sway
6 = strong wind / wind speed 28 mph / large branches move
7 = near gale / wind speed 42 mph / whole trees sway
8 = gale / wind speed 42 mph / difficult to walk into the wind
9 = severe gale / wind speed 50 mph / branches blown from trees
10 = storm / wind speed 58 mph / trees blown down
11 = severe storm / wind speed 68 mph / serious damage to buildings
12 = hurricane / wind speed greater than 73 mph / widespread damage
You can write only the number and the name of each severity if you wish. Take your wind detector outside, orient north correctly and use it to determine wind direction and speed and record them.
- Francis Beaufort was a sailor who developed this wind measuring system, find out more about him.
- Learn how an anemometer works.
- After you have kept track of the wind for a week or more, you can make a line graph using the Beaufort numbers to show what the wind was each day.
- Kids who enjoy art projects can turn their wind detector into one by decorating the plate.
- Learn about the most recent hurricanes. Where were they and what damage did they do?