Measure Wind Speed With a Pinwheel

By Sara B Sweetman, PhD

Sep 5, 2025

How fast is the wind blowing where you live? As we see on “Weather Hunters,” meteorologists use a tool called an anemometer to measure wind speed. Anemometers work because they have arms with cup-like structures that get pushed by the wind. The faster the wind blows, the more the cups are moved, and the quicker they spin — just like a pinwheel!

You can measure the wind speed where you live by building your own pinwheel, which works like an anemometer.

Materials

Directions

Start by coloring only one of the four sections of this pinwheel. By coloring just one section, you’ll be better able to count the times the pinwheel spins in the wind.

Cut out the pinwheel. (Remember to stop at the end of the dotted lines!)

Place the center of the pinwheel on the eraser end of a pencil. Gently bring the tips of the pinwheel into the center and hold them to the pencil eraser with your finger. (Be sure you don’t fold or crease the paper!)

Push a pushpin through the four tips, the center of the paper, and into the eraser. Once the pin is in, pull it back up just a little so it still holds the pinwheel to the pencil, but is not too tight, allowing the paper pinwheel to spin.

Go outdoors and hold your pinwheel up to the wind. Notice how it spins! Each time the colored section of the pinwheel passes the pencil is one rotation. Practice counting the rotations together.

Set a timer for one minute. Have your child count the number of times the pinwheel spins. If it’s too windy, it might be tricky to count the number of times the pinwheel spins one full rotation!

Create a T-chart on a piece of paper, similar to the one shown in the example. Record your first location and the number of spins in one minute. Now, take the pinwheel to an area with more wind or less wind. Count the number of spins from that location and record it on your chart, too. Ask your child, “How do you know which place was the windiest?”