why does formation of rain occurs
Answers
By the help of
Water cycle
When warm, wet air rises, it cools, and water vapor condenses out to form clouds. A cloud is made up of small drops of water or ice crystals, depending on its height and how cold is the surrounding air. Height and temperature also determine whether any "precipitation" which results (from the Latin for "to fall from") will be rain or the hail associated with thunderstorms, or the snow, sleet and freezing rain we associate with winter weather.
To form rain, water vapor needs what's called a "condensation nucleus", which can be tiny particles of dust, or pollen, swept up high into the atmosphere. When the condensing droplets that form the cloud get large and heavy enough to overcome the upward pressure of convection, they begin to fall. If the temperature all the way to the ground is above freezing, then--it's raining! When ice crystals form high up in the cloud, and it's below the freezing point of water all the way down, then you get snow. But when there are alternating layers of air above and below freezing, you get other types of precipitation