A Droplet’s Journey

The Sun warms water in seas, lakes and rivers. Some liquid water changes into invisible water vapour and rises into the air. Higher in the cooler air, the vapour cools and changes into tiny liquid droplets. This is condensation, and the droplets gather to form clouds. When droplets join together and become too heavy to stay in the cloud, water falls as precipitation. It may fall as rain, snow, sleet or hail. Water then collects in rivers, lakes and seas, or flows over land into them. The Sun can warm it again, so the cycle continues. Water can also soak into the ground, where it may later flow towards a river.