How do we see the wind?

A big layer of air called the atmosphere surrounds Earth. The air within this layer moves from place to place when it warms up or cools down. This moving air is called wind. Winds move moisture and heat around the world and also produce much of our weather. You can see wind—which sometimes moves slowly and is barely noticeable—blowing through the trees. You can also sometimes feel wind as a gentle breeze in your face and in your hair. At other times, the air can move very quickly and become a hurricane, blowing down trees and damaging cars and buildings.