Due to intense sun rays, water from the water bodies starts evaporating and travels up into the atmosphere in the form of water vapor , as it rises above the surface,the temperature decreases and the evaporated water starts undergoing condensation and is converted into water droplets leading to the formation of clouds.When the clouds get heavy and are not able to hold the weight of more water droplets they scatter and fall down on the Earth's surface in the form of precipitation or in simple words rain.

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due to the heat during the day time a large amount of water gets evaporated and goes into the air from various water bodies.the other part of the water reaches the atmosphere through transpiration and respiration.the heated air rises,expands and cools to form tiny droplets.these droplets grow bigger,expand and form clouds with the help of suspended dust particles.