How is rain formed?

Rain is part of the water cycle. The Sun heats water in oceans, rivers and lakes, and it evaporates into water vapour. As the warm, moist air rises, it cools, and the vapour condenses on tiny particles of dust or salt, forming droplets that make clouds.

Inside clouds, droplets bump into each other and join to become bigger and heavier. When they become too heavy for the air to hold up, they fall as rain. In very cold clouds, ice crystals form and may fall as snow or melt into rain on the way down.