What makes the wind blow?

1. 1

   Roo says

   The sun warms the air, but not everywhere the same. Where the air gets warm, it rises up high. Cooler air rushes in to fill the space it left behind. All that moving air is the wind!

   For ages 4–7
   Hear Roo

   Checked against Why does wind blow? (NOAA SciJinks)

2. 2

   Why does the cooler air rush in?

   In cool air, the tiny bits of air are crowded close together. Where warm air has risen away, there's more room. Air always spreads out from crowded places into roomy ones, like people on a bus spreading out to the empty seats. The bigger the difference, the faster the wind.

   For ages 6–9
   Hear Roo

   Checked against Why does wind blow? (NOAA SciJinks)

In Lil' Phil, reaching the bottom of this wonder earns a sticker for Roo's collection.

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