Make an Anemometer

Well first, what’s an anemometer? What are you getting yourself into?? Anemometer is the instrument we use to measure wind speed! And you can make one of these at home. 

 Also heads up, this is one of the longest videos and blog posts so far. The steps are easy enough, but this will take a little more time to set up than some of our more speedy experiments we’ve done so far. Click here to watch me assemble it and talk you through the process. If you need to see what it’s supposed to look like at any point, refer back to that video!

What you need: 

  • Single hole punch (I used a belt loop punch)

  • 5 small paper cups

  • 3 thin wooden dowels

  • Empty 16 oz water bottle

  • Scissors

  • Duct tape 

What you do: 

  • Use the hole punch to make one hole in the side of four of the paper cups (all roughly in the same place) and four equally-spaced holes around the rim of the fifth

    • PRO TIP: on that fifth cup, the two holes opposite each other need to be in the same spot.  The other set of two holes opposite each other should be slightly lower than the first set.  Here’s the video of me doing this experiment which better explains how to line up the holes on that fifth cup, so this works perfectly on the first try. 

  • Slide two wooden dowels through the holes in the center cup to make an “X”

  • Add the four other cups to the ends of the dowels, so they’re all facing the same way.  Tape them in place. 

  • With the last wooden dowel, poke a hole in the bottom of the center cup and tape it to the center of the “X”. 

    • PRO TIP: use the scissors to poke the hole in the bottom of the cup.  The dowel didn’t help much. 

  • Put the center dowel into the water bottle

To calibrate: ask an adult to get in the car with you.  Drive 10 mph (adult: just set the cruise control on a long stretch of road), hold your anemometer out the window and count how many times it spins around in 30 seconds. 

  • PRO TIP: use one paper cup that’s a different color than the others, so it’s easier to pick out when it spins around one full time. 

Do the math! In 30 seconds your anemometer spun Z number of times when the wind was blowing 10 mph.  If your anemometer spins 40 times, how many mph is the wind blowing? 

Adults: if you need some help with that math, send me a message using the contact form here on the website and I’ll help! 

Hannah Strong