Clouds

When you look up at the sky, you may see clouds. In temperate or mild climates, there are usually at least a few clouds and, sometimes, cloud cover is total. Clouds are dense masses of water drops or ice crystals so light and small that they float on the air. Clouds form when rising air cools to a point where it can no longer contain its water vapour, and so the vapour condenses. There are three basic forms, or shapes, of clouds- puffy cumulus, layered stratus, and feathery cirrus- but each form can vary to make many different cloud types. The type of cloud depends on how high the air rises and its temperature.