How to Build a Simple Anemometer to Measure Wind Speed with Your Kids

Learn to build a homemade anemometer with household items to measure wind speed in your backyard.

  1. Gather Your Materials. You'll need five small paper cups (like Dixie cups), two wooden skewers or thin dowels, a pencil with an eraser, a small nail or push pin, a stapler, colored markers or paint, and a watch with a second hand. Having everything ready before you start makes the project flow smoothly and keeps kids engaged.
  2. Prepare the Cups. Take four cups and use the nail to poke a hole near the rim of each cup, making sure the holes are at the same height. These holes should be just big enough for the wooden skewers to fit through snugly. Color one cup differently from the others – this will be your marker cup to help count rotations. Let kids choose the colors and do the decorating to make it their own project.
  3. Create the Cross Structure. Push the two wooden skewers through the holes in the cups, creating a cross shape with a cup at each end. The cups should all face the same direction – imagine they're all trying to catch the wind from the same side. Adjust the skewers so they cross exactly in the middle, then secure this intersection with a small piece of tape if needed.
  4. Attach to the Base. Take the fifth cup and flip it upside down – this becomes your base. Push the pencil through the bottom of this cup, eraser-end first, so the pencil point sticks up. Now carefully push the nail or push pin through the center where your skewers cross, then into the pencil eraser. The cross structure should spin freely on this pivot point.
  5. Test Your Anemometer. Blow gently on your anemometer or take it outside on a breezy day. The cups should catch the wind and spin around smoothly. If it's not spinning well, check that the nail isn't pushed too far into the eraser – it needs to move freely. Make sure the cups are all facing the same direction for best results.
  6. Measure Wind Speed. To measure wind speed, count how many times your colored marker cup passes a fixed point in 30 seconds, then multiply by two to get rotations per minute. Keep a simple chart to record your measurements at different times of day or in different weather conditions. While this won't give you exact wind speeds like professional tools, it will show you when wind is stronger or weaker.