During a strom, there are thick, dark clouds in the sky, very strong winds and often heavy rain or snow. Sometimes, there is thunder and lightning, too. Stroms and other kinds of weather happen all over the world. Weather is formed in the air that surrounds that Earth. You can see weather from space. This picture shows white, swirling clouds. The gaps between the clouds are clear skies. The type of weather depends on how hot, cold, dry or damp the air is. Where the air is hot and dry, the weather is sunny and there's no rain. Cold and damp air makes cloudy, foggy, rainny or snowy weather. Many storms happen where the air becomes hot and damp. Strom clouds form when the air is warm and damp. Damp air is filled with very tiny water droplets, so small you can't see them. All stroms come with strong winds. Winds is moving air. It happens when hot air rises and cold air rushes in to take its place. Snowstroms happen when the air is very cold. Small balls of ice called hailstones, form when water droplets are blown around inside a storm cloud.