Did you know a home barometer is used to measure air pressure? You can even use it to predict the weather. High pressure indicates cool, dry weather. Low pressure indicates cloudy, wet, rainy, or snowy weather. 

How Atmospheric Pressure Works

Atmospheric pressure can vary depending on the altitude where you reside. In higher altitudes, there are less air molecules bouncing around. Gravity pulls those molecules toward Earth’s core. On the surface, the molecules are closer together, creating higher pressure.

Making a home barometer is a challenging yet fun project kids will enjoy. They can use their creation to make their very own predictions about the weather.

The Directions

What You Will Need:

  • a glass jar
  • a balloon
  • a rubber band
  • a straw
  • a toothpick
  • Elmer’s glue (or similar type)
  • tape
  • paper
  • an ink pen or fine marker

Steps:

1. Blow up the balloon. Doing so increases the pressure outward from the inside of the balloon.

2. Release the air from the balloon.

3. Cut off and discard the neck of the balloon.

4. Stretch the bottom part of the balloon over the top of the jar. Secure the balloon with the rubber band.

5. Tape the toothpick to the end of the straw.

TIP: Place tape in multiple places to keep everything secure.

6. Place a drop of liquid glue in the center of the balloon.

7. Set the straw on top of the glue. Then, tape the straw to the center of the balloon on top of the jar to keep everything secure. Gently remove the tape after the glue is dry.

8. As you wait for the glue to dry, draw measurement lines on the piece of paper and mount it on the wall behind where you are going to set your barometer.  

9. The measurement lines should be beyond the length of the toothpick end of the straw where you mounted the paper on the wall.

10. Make sure the longer line is aligned to the tip of the toothpick.

11. Check your barometer every few days, and mark any changes at the end of the toothpick on your paper.

12. Keep a written log of the weather, recording regular observations and how the weather affects the barometer's movements.

How to Read Your Findings:

1. If the toothpick end of the straw points upward from the center mark, the air pressure is high, so the balloon will face downward.

2. If the toothpick end of the straw points downward from the center mark, the air pressure is lower, which allows the air inside the jar to press upward on the balloon.

Sherry Garrett has worked for Lincoln Learning Solutions since September 2020. She graduated from Central Michigan University with a bachelor’s degree in Music Education and certification in Child Development from Northwestern and Early Childhood Administration from Grand Valley State University. She holds a master’s degree in Educational Technology from Central Michigan University. 

Garrett and her sons have won the American Satin Rabbit Breeders Association national sweepstakes. She is currently the secretary/treasurer of the American Satin Rabbit Breeders Association and the Michigan State Rabbit Breeders Association secretary. She is a 4-H leader and sits on the board of directors of the Osceola County Fair to provide quality educational experiences for youth.