Winds are formed when the Sun warms up the Earth's surface and the air above it. The warm air begins to rise, and new air flows to fill the space left by it. 

Winds often decrease the air temperature, as the new air that flows to replace warm air is usually cold. The flow of air itself also has a cooling effect. You can try this yourself by blowing air on the back of your hand. 

Winds can sometimes be dangerous, especially in shore areas. Storms can make trees fall down and cause damage to buildings. The scientists that focus on studying and predicting the weather, meteorologists, try to warn people about storms and other dangerous weather conditions by issuing wind and storm warnings. In the summer, storms are often connected to thunder showers.

Wind speed is measured in meters per second (m/s). This unit describes how many meters the wind travels during the course of one second.