How does a cloud form? When is the best time to see a rainbow in the sky? Why do ice cubes shrink in the freezer? The answers to these questions all involve water. So do the reasons why we have rain and snow. To understand weather, we have to know what happens to water at different temperatures, on the ground and in the air. In this fact-packed book, discover what happens when water changes from a liquid into a gas or a solid, and much more.