Activity overview

Run the activity

1. Plan an investigation around a Big Question. What do the pupils already know about clouds? 

• What do you notice when you look at clouds in the sky? 
• What do you think clouds are made of? 
• Why do clouds look different at different times? 
• How do you think clouds get up into the sky? 
• How could we find out more about how clouds are formed? 

2. How will the group explore the question? Prompt pupils to explain their ideas, qualify them and refine them based on views expressed by other people. What is their plan for the investigation? 

3. Ask the class to imagine they had to present their investigation at a school assembly or to their family, how would they show their action plan? 

Background science

Clouds are made up of billions of water droplets (or ice crystals) floating in the sky. These are tiny, so small that we can’t see them with our eyes.  

A typical cumulus cloud (the sort we like to draw!) can weigh 500 tonnes which is as much as 100 elephants!  So, how do clouds get up into the sky?  The clouds of tiny water droplets in the sky are a result of three processes: 

1. Evaporation: This is the process of liquid water turning into the gas, water vapour. Evaporation differs from boiling because it only occurs at the water’s surface and can take place at temperatures below 100 °C (water’s boiling point). Around the world, water evaporates from large bodies of water such as oceans, as well as smaller puddles, plants and the soil. Evaporation increases when the Sun heats the water’s surface.

2. Warm air rising: Heat from the Sun warms the ground and the air at ground level. Warm, humid air rises and cools down as it goes up. When the water vapour in the air cools, it sticks to tiny particles of dust in the air. 

3. Condensation: This is the process of water vapour gas turning into liquid water – it is the reverse of evaporation. Water vapour condenses on the surface of the tiny particles of dust in the air. This eventually forms a tiny droplet of water. If it is cold enough it may become an ice crystal.

The water droplets are so tiny and spread out that they stay afloat on the warm air rising beneath the cloud. However, when the tiny water droplets bump into each other, they combine to make bigger droplets. When they get too heavy, they fall from the sky as rain (or hail or snow). 

Clouds were once the best way of predicting the weather. Dark clouds low in the sky indicate rain, whereas thin clouds high in the sky suggest that the weather will be sunny. They are still important for weather scientists (meteorologists) today.  

Watch out for... 

Many people think that clouds are made of water vapour, but water vapour is an invisible gas. In fact, clouds are made up of billions of water droplets (or ice crystals) floating in the sky. These are tiny, so small that we can’t see them with our eyes. This does not need to be corrected during the session, but you can pick it up later. 

Take it further

Activities 

Children could use secondary sources to research the Water Cycle and how clouds are formed. They could present their findings using drama, making a poster or an interactive slide  presentation. Making a water cycle in a bag to see condensation works well when fixed on to the classroom window.    

There is this simple cloud colour viewer from MetLink which could help children spot patterns and make predictions. Does it always rain from dark clouds? 

Children who find studying the clouds fascinating might like to know that the type of scientist who studies the weather is called a meteorologist. They could meet Professor Paola A. Arias who is a climate scientist who studies the clouds using the A Scientist Just Like Me resources from the Primary Science Teaching Trust. 

Linked Explorify activities- our recommendations: 

All the stages of the water cycle can be seen in our What’s Going On? Never ending story and some of the stages can be spotted in  A sudden downpour and Liquid of life. 

There is also  Cloud watching and Water to recap on key points.  

Watch 

Learn about the stages of the water cycle in this BBC clip,  

Watch this video to find out more about clouds and how they form. This video from the Science Museum explains how clouds form and may inspire some cross-curricular work such as poetry or art based on clouds. Watch snippets of flying through clouds to observe clouds forming, rising and casting shadows on the ground below