Cloud in a Jar Experiment

Creating a cloud in a jar is a great way to learn how clouds form and how cloud seeding works.

Clouds form when water vapour condenses or freezes. Water vapour rises, cools and condenses on particles in the air to form a cloud. When clouds become too heavy to be supported by upward air currents, precipitation falls.

This simple activity demonstrates how clouds form. I used smoke as the particles the water vapour condenses on, but in the natural environment, particles can be many different things in the atmosphere, including dust or pollen.

How to make a cloud in a jar

You’ll need

A transparent glass jar

Warm water – not boiling

Kitchen foil

Ice

Match

As this activity uses a lit match, an adult should supervise.

Cloud in a Jar Instructions

Fill the jar about one quarter full with warm water.

Ask an adult to light a match, place it slightly inside the jar and blow it out.

Place the foil over the lid of the jar and place ice over the top.

Watch as a cloud forms inside the jar.

When you’ve seen the cloud form, remove the foil. The cloud will escape from the jar.

More weather science experiments for kids

Find out how to forecast the weather with a pinecone.

Create a water cycle model.

Make a rain cloud in a jar using shaving foam and food colouring.

Last Updated on May 12, 2025 by Emma Vanstone