Make a Cloud in a Jar

If you look up, clouds are above of us much of the time, floating in the sky. Have you ever wondered about how these fluffy looking masses are formed? In this activity we’ll make our own cloud in a jar to learn a bit about how clouds are formed in the sky. 


How Do Clouds Form in Nature?

The process of evaporation and condensation that we’ll use in this experiment is the same process that occurs in nature to form clouds. Water on Earth’s surface evaporates, rises, cools, then condenses into tiny water droplets to form clouds. Water vapour then needs something to condense onto:  in our experiment, we will use hairspray for it to condense onto. In nature, the vapour may condense onto dust, pollen, or air pollution. 

Did You Know:

Clouds are not weightless! Despite their fluffy appearance, as a result of the water they hold, clouds can weigh millions of pounds (or even billions of pounds in the case of some thunderstorms)!

Did You Know:

Clouds can move! Clouds can travel at more than 160 km/hour (that’s faster than cars drive on the highway!) with the jet stream.

Did You Know:

A phase change from gas to liquid is called condensation, and a phase change the opposite way, from liquid to gas, is called evaporation.


To make our cloud in a jar, you will need the following materials:

  • A jar with a lid
  • Hot water (1/3 cup)
  • Food colouring (optional)
  • Measuring cup
  • Ice (about 5 cubes)
  • Hairspray


  1. Pour ⅓ cup of hot water into the jar. Warm the sides of the jar as well by swirling the hot water around in the jar. Add a few drops of food colouring if you would like to add some colour to your experiment!
  2. Flip the lid upside down, and place it upside down on top of the jar.
  3. Put several ice cubes onto the upside down lid on top of the jar. Keep the upside down lid filled with ice cubes on top of the jar for at least 20 seconds.
  4. Remove the lid, and quickly spray a bit of hairspray into the jar. Put the upside down lid with the ice cubes back on top of the jar.
  5. Make an observation! What do you see happening inside of your jar? You should begin to see clouds forming above the water!

Why Do You See Clouds in the Jar?

The water at the bottom of the jar is warm. When water is warmed, some evaporates into a gas form, called water vapour. The water vapour rises to the top of the jar, where it is cooled down by the ice on top of the lid. When water vapour cools down, it forms condensation. That condensation settles on the hair spray inside of the jar, forming a cloud. Pretty cool!

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