How does topography affect the weather?

Mountains and valleys act like playgrounds for air, changing how it moves and feels.

Imagine you're riding your bike up a big hill, it’s harder work than going down. The same thing happens with air when it goes over mountains. When the wind climbs up a mountain, it slows down and cools off, just like you do on your bike ride. On the other side of the mountain, the air speeds up again and warms up, kind of like zooming downhill.

When air goes over a mountain, it can carry moisture, like when you bring water in a backpack. As the air rises, it cools down, and that moisture turns into clouds and then rain on the top of the mountain. The side that faces the wind often gets more rain, while the other side, called the leeward side, is drier, like when you're sitting in the shade after a sunny day.

Valleys can trap cold air, making it feel like being stuck in a chilly room, while hills can let warm air roll down, just like when you slide down a slide on a sunny afternoon.