One of the most frequently asked questions on school visits (especially from the younger kids) is, “How are clouds made?”

Here’s an experiment that is great for kids (even the younger ones) that is really fun and really easy to do:

Cloud In A Jar:

What you’ll need:
-A glass jar with lid
-About 1/3 cup hot water
-Ice cubes

  1. Pour the hot water into the glass jar. Swirl the water around the jar a bit to get the sides warm.
  2. Put the lid upside down on top of the jar. Place a few ice cubes on top of the lid that is on top of the jar for about 20-30 seconds.
  3. Lift the lid off the jar and spray hairspray inside of the jar. Then immediately put the lid with the ice cubes back on top of the jar.
  4. Watch the cloud form!
  5. Once you see a good amount of condensation in the jar remove the lid and see the “cloud” escape.

What is happening?

Clouds are made up of water vapor! The warm water in the jar turns into water vapor and rises to the top of the jar. When the water vapor touches the cold lid it cools and condenses. But, a cloud forms when water vapor can cling on to something. In our atmosphere water vapor will cling on to dust, pollution, pollen, etc. to create clouds. The water vapor in our experiment clings onto the hairspray to create the cloud.