What is the water cycle?
The water cycle is the journey that water takes as it moves around our planet. Water is constantly changing from liquid to gas to solid and back again. About 97% of Earth's water is in the oceans, but water doesn't just stay there — it's always on the move!
The water cycle has three main stages: evaporation, condensation, and precipitation. These processes work together to keep water moving around the Earth.
Evaporation: water rises up
When the sun heats water in oceans, lakes, and rivers, something amazing happens. The water turns into an invisible gas called water vapour and floats up into the air. This process is called evaporation.
Think of it like: leaving a wet puddle outside on a sunny day. The water doesn't disappear — it transforms into an invisible gas that rises into the sky.
Plants also release water into the air through their leaves in a process called transpiration. Together, evaporation and transpiration are sometimes called evapotranspiration.
Condensation: water forms clouds
As water vapour rises higher into the atmosphere, it gets colder. When the temperature drops enough, the invisible gas turns back into tiny water droplets. This is called condensation. Billions of these droplets cluster together to form clouds.
Think of it like: when you breathe onto a cold window and it gets foggy. Your warm breath is water vapour, and the cold glass turns it into water droplets you can see.
Precipitation: water falls back to Earth
When clouds get heavy with water droplets, they fall back to Earth as precipitation. This can be rain, snow, sleet, or hail depending on the temperature. Some water soaks into the ground as groundwater, some flows into rivers and streams, and some collects in oceans and lakes.
Then the whole cycle starts again! Water that soaks into the soil is used by plants and animals, but eventually it evaporates back into the atmosphere. This endless journey has been happening for billions of years and keeps our planet alive.