Signed, Brad - Whitesburg Elementary. It seems to me that rain is able to read people's mind. When you need a good shower, there's never a cloud in the sky. On the other hand, nothing brings out the storm clouds like an outdoor wedding. That's why people have been trying to predict and understand the weather since the beginning of history.
Rain is caused by a mixing of water, air, and heat in the atmosphere.
First, the sun beats down on oceans, lakes, and even mud puddles causing the water to evaporate. While the sun is evaporating water, it is also heating up pockets of air as well. Just like a hot air balloon, these pockets of warm, moist air begin to rise into the atmosphere taking water with them. Sometimes these small pockets will mix with other pockets to make larger air masses. As the air masses rise, they also begin to cool.