How evaporation causes cooling?

Water and other liquids absorb heat energy from their surroundings when they evaporate. Since the high-energy molecules leave the liquid's surface, the remaining liquid molecules have less average...

it is the evaporation to melt the rain

Energy must be put into whatever is being evaporated (to turn int from liquid to gas). An example is when one sweats, the body cools as the sweat evaporates, because the energy for the sweat (water)...

Cooling does not cause evaporation. Warming does. This is because as the air warms up, there's more space for water vapor in it. Water evaporates and turns into water vapor to fill this space.

Quick and dirty answer: Because the liquid that is evaporating must absorb heat in order to do so. It is much like melting ice. The ice melts because is absorbs heat. If there is no heat for it to...