The Water Cycle

Discover how water moves through Earth's systems: evaporation, condensation, and precipitation.

What is the Water Cycle?

The water cycle (also called the hydrological cycle) describes how water continuously moves on, above, and below the surface of the Earth.

The Four Main Stages

Evaporation: The sun heats up water in rivers, lakes, and oceans, turning liquid water into water vapor that rises into the atmosphere. Plants also release water vapor through their leaves in a process called transpiration.

Condensation: As water vapor rises, it cools and turns back into tiny liquid water droplets, forming clouds and fog.

Precipitation: When water droplets in clouds combine and become heavy enough, they fall to Earth as rain, snow, sleet, or hail.

Collection: Water collects in oceans, rivers, lakes, and groundwater. The cycle begins again.

Why Does the Water Cycle Matter?

The water cycle distributes freshwater around the planet, regulates temperature and weather patterns, and supports all living things — no water, no life.