Air pressure refers to the weight of the Earth's atmosphere pressing down on everything at the surface.This means hundreds of pounds of pressure are pressing on us from all sides, all the time! Of course air pressure is one of the most important factors in determine the weather.
Low air pressure causes air to rise and potentially mix with warmer air, which can produce thunderstorms. High air pressure is associated with calm weather. Check out the experiments page for "Pressure Pete's Crazy Balloon" demonstration. Also pay attention to the question Terri poses on our YouTube video, too. Both of these fun demonstrations are guaranteed to wow and make learning about air pressure fun!