Not all clouds are up in the sky. Some are on the ground! What we call fog is simply a cloud that is next to the ground. All air has some moisture in the form of water vapor. When warm, moist air cools, it often can no longer hold its moisture as water vapor. The extra moisture changes (condenses) into small drops of water which can be seen. So a cloud is a collection of moisture in the air.
The air currents keep the cloud up in the sky. But if the cooling continues, more and more vapor is changed into drops. Gradually, the tiny droplets become larger and larger as they collect more moisture. When the drops become so large that they can no longer be held up by the air currents, they fall to the ground as rain.
Clouds can form at many different heights above the earth. In fact, clouds are divided into types according to their distance from the earth. The four main families of clouds are clouds, middle clouds, low clouds, and clouds which may extend through all levels.
How Do Clouds Get Water?
Clouds are created when water vapor, an invisible gas, turns into liquid water droplets. These water droplets form on tiny particles, like dust, that are floating in the air.