Book 4, Question 81
Why Does the Wind Blow?
Wind is air on the move! The sun warms some places more than others. Warm air rises, and cooler air slides in to take its place. Wind is invisible. We see what it pushes, like flags, leaves, and waves.
From the book
Page from A Million Whys Book 4
More fun facts
- The Sun warms the Earth unevenly, so some places get warmer than others.
- When air warms up, its molecules move faster, spread out and rise.
- Cold air is heavier and its molecules stay closer together.
- Wind is air rushing from where it is packed tightly toward where it is thinner.
- Rising air cools and can make clouds and rain. Sinking air warms and usually brings fair weather.
- Lines on a weather map that connect places with the same air pressure are called isobars.
- The air can be still one day, and the next day gusts can be strong enough to knock down trees.
Questions kids ask
What do the H and L on a weather map mean?
H means high pressure, which often brings fair weather. L means low pressure, which often brings clouds and rain.