How do clouds work?

Ever wondered how clouds work? Or why it rains? This easy science demonstration helps us to see what happens all the way up in the clouds. Easy to do and you probably have all the equipment you need already.

You will need:

  • A glass
  • Water
  • Food colouring
  • Shaving foam

    Photo from Toby& science demonstration

    Photo from Toby&

  • Pipette / dropper


  • Fill the glass with water , leaving some space at the top. The water represents the sky.
  • Put some shaving foam on top of the water, so it sits on top like a cloud.
  • Using a pipette/dropper , drip some food colouring onto the ‘cloud’ one drop at a time, until it starts to break through the bottom of the shaving foam into the water, like rain from a cloud.
  • Use different colours or make lots of different clouds!

The Science Bit:

All air contains water, and as it rises into the sky it cools and then condenses around dust particles and forms droplets. When there are lots of these droplets together it forms a cloud.

Clouds start to look grey when they get thicker as the light from the sun can’t get through as easily. When there are more droplets, some start to group together to make bigger droplets. When this happen they can get too heavy and gravity pulls them down as rain.

If it is very cold the droplets may freeze into ice crystals, this is how we get snow.