Have you ever seen trees blowing in the breeze? Or a piece of paper fly across the street? What about a kite flying up into the air? A sailboat glide across the open sea? What do you think makes these things move? Wind, of course! Wind is air that moves. Wind speed can vary. Sometimes the wind blows gently but other times it blows quite hard.
How is wind created? Wind is caused by air moving. When cool air and warm air meet, the cool air moves underneath the warm air. This movement of the air causes wind. Wind direction can be measured with a wind vane or a wind sock. Wind speed is measured with an instrument called an anemometer.
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