What Causes Wind
Understand what causes wind: the Sun heats the Earth's surface unevenly, warm air rises because it is lighter, and cooler air rushes in to take its place — this movement of air is wind
What a learner can do afterwards
- Explain that the Sun heats Earth's surface unevenly
- State that warm air rises and cooler air moves in to replace it
- Define this air movement as wind
The lesson
You already know that wind is moving air. But what makes air start moving in the first place? It all begins with the Sun. The Sun does not heat every part of the Earth by the same amount. Sandy beaches, dark roads, and open fields heat up fast. Oceans, lakes, and shady forests warm up much more slowly.
When the ground gets hot, it warms the air sitting right above it. Warm air is lighter than cool air, so it floats upward, the same way a hot air balloon lifts off the ground. As that warm air rises, it leaves a gap near the ground.
Picture a hot afternoon at the beach. The sand gets scorching hot, but the ocean stays cool. The hot air above the sand rises up and away. Cooler air from over the water rushes in to fill the space it left behind. That rush of air blowing past you is wind.
Whenever you feel wind, remember: some patch of ground got hotter than the ground nearby, and air is rushing in to even things out.
The Sun heats the ground unevenly, warm air rises because it is lighter, and cooler air rushes in to take its place. That moving air is wind.
Watch it
Where it sits
Learn first
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.