The Water Cycle

weather · earth science · continuous process

Oceans drive the cycle. About 86% of all the water that evaporates into the air comes from the ocean. The sun heats ocean water, turning it into invisible water vapor that rises into the sky.

Water changes forms. As water vapor rises high in the cool air, it condenses into tiny water droplets that form clouds. These droplets can freeze into ice crystals if it gets cold enough up there.

Rain brings water back down. When clouds get full of water droplets or ice crystals, they become too heavy and fall as precipitation, water, snow, or sleet back to Earth's surface.

Water soaks into soil. When water lands on the ground, some of it infiltrates deep into the soil and rock below, filling underground reserves called aquifers that plants and animals depend on.

Plants release water too. Plants pull water up through their roots and release water vapor through their leaves in a process called transpiration, which adds moisture back to the atmosphere.