The Water Cycle
Watch water travel from the ocean to the sky to the mountains and back again. Tap any stage to learn more.
Water never leaves Earth
The water you drink today is the same water the dinosaurs drank! Water moves around Earth in a cycle — it changes between liquid, gas (vapor), and solid (ice), but it never disappears.
The cycle has four main stages: evaporation (water rises as vapor), condensation (vapor forms clouds), precipitation (water falls as rain or snow), and collection (water gathers in oceans, lakes, and rivers).
Interactive water cycle
Click any stage in the diagram, or use the buttons below to learn about each part.
1. Evaporation
The Sun heats the ocean. Water turns into vapor (an invisible gas) and rises into the sky. This is called evaporation. Heat gives water molecules energy to escape from the liquid surface.
Why the cycle matters
The water cycle gives us fresh water to drink. When ocean water evaporates, the salt is left behind. The fresh water falls as rain, fills rivers and lakes, and we can drink it. Without the water cycle, all water would stay in the ocean and we'd have nothing to drink!
Why this matters
The water cycle is how Earth shares water with everyone. A drop of rain in your town might have evaporated from the Amazon rainforest, drifted across the ocean as a cloud, and fallen on your head. We all share the same water.
Understanding the water cycle helps us predict droughts, floods, and storms. It helps farmers know when to plant. It helps cities plan their water supply. It reminds us that water is precious — there is no new water, only the same water moving around.