My Science School

Winds carry warm and cold air around the world. Knowing which way the wind is blowing is a useful guide to the type of weather we can expect. Around the world, there are many differences in temperature. Air in contact with hot land or sea is warmed. As warm air is lighter than cooler air, it rises. Cooler air then moves in to take its place. This movement of air is what we call wind.

Winds can be extremely powerful; they can knock down trees, and can push along boats fitted with sails. The map shows the routes of the main winds across the globe. These routes were once followed by sailing ships carrying their cargoes around the world.

Sea breezes

As the Sun shines, air over the land is heated more than air over the sea, and this hot air rises. Cooler air from over the sea moves in to take its place.

The hot air cools as it rises, but it does not fall straight back down. Instead, it spreads out over the sea and falls down there. This circular air current causes an onshore breeze.

The map shows the major winds of the world.

Yachts with the wind in their sails