The Water Cycle
- Earth & Space
- Ages 8–11 · Grades 3–5
What you’ll find out
- The Sun powers the water cycle by evaporating water into invisible water vapour.
- Rising vapour cools and condenses into droplets that form clouds.
- Droplets fall as precipitation and flow back to the sea, so the cycle repeats.
No sign-up and no real names. In the lesson you check your understanding as you read, and practise until it sticks.
Up into the sky
Water is always on the move around our planet, rising into the sky and falling back down again in a never-ending loop called the water cycle. It begins when the Sun warms water in oceans, lakes, rivers and even puddles. Some of that water turns into an invisible gas called water vapour, which rises into the air. This change from liquid to gas is called evaporation, and it is the reason puddles disappear on a warm, sunny day.
Clouds, rain and back again
High up, the air is much colder. As water vapour rises, it cools and turns back into tiny droplets of liquid water. This change is called condensation, and billions of these droplets together make a cloud. Inside the cloud, droplets bump together and grow bigger and heavier until they fall as rain, or as snow or hail when it is cold enough. This is called precipitation. Rivers and streams then carry the water back to the sea, and the cycle begins again.
Curriculum links: NGSS 5-ESS2-1 · England KS2: States of matter · Cambridge Primary Stages 4–6: Earth and space · NCERT Environmental Studies, Classes 3–5