How does rain happen? Long ago the Ashanti people believed that Anansi, the Spider, brought the rains that would put out fires in the jungle. In old Britain, the legendary Green Man was supposed to have rainmaking powers, and Zeus brought the rains for the ancient Greeks.
Today, we know that when warm, wet air rises into the sky and cools off, its water condenses out of the clouds as rain. Rain and snow can also happen when a batch of warm air meets a batch of cool air. The two kinds of air usually do not mix. The warm air is less dense than the cool air and will slide right over it. As the warm air goes higher, it cools off, and the moisture separates or condenses out of the cooled air and falls as a slow, steady rain.