The next time you are out and about on a windy day, notice how the wind lifts and moves some things but not other things. Look for dry leaves or paper caught up in the wind.
What can you tell about the wind by watching things blow around? Can you tell how soft or hard it is blowing? Can you tell which way it is blowing?
For an extension to this activity, try making soap bubbles or blowing up some balloons and letting them go into the wind one by one. Observe the way they move in the wind. Do they go up, do they get pushed along the ground, or do they do a little of both?