Wind

Wind is moving air.

Hot air goes up, and cold air goes down. The difference in air temperature causes wind, which moves air from one place to another. This is why clouds move.

When there is no wind or we can’t feel any wind, we say that it is calm.

A little wind is called a breeze. A breeze moves the leaves on the trees. It can help us feel cooler on a hot day.

A gale is a strong wind. A gale moves the branches on trees and can sometimes blow trees down!

A hurricane is a very strong wind. A hurricane can destroy houses and other buildings.

Video | How wind is formed.
Via ourplanet.org.uk