Precipitation is any form of moisture which falls to the earth. This includes rain, snow, hail and sleet. Precipitation occurs when water vapour cools. These tiny droplets of water from clouds.
Complex forces cause the water droplets to fall as rainfall.
All rain is the same. It happens as the result of warm, moist air being cooled, leading to condensation and in turn rain. The following examples show three different ways air is cooled causing rainfall. Relief Rainfall Stage 1. Warm wet air is forced to rise over high land.