Have you ever wondered how fog forms? Here’s an easy experiment you can do at home that lets you watch fog form before your eyes!

You’ll need a few supplies to get started:

1- A clean glass jar
2- Enough hot water to fill the jar *since you’re dealing with hot water, be careful and have an adult nearby
3- A small strainer (or make your own. See how I did it in the video)
4- Ice cubes

First fill the jar to the top with hot water. Let this sit for a minute or two. After a couple minutes have passed, empty the jar so that about 1″ of water is left in the bottom. Place your strainer over the top of the jar. Fill the strainer up with ice, just enough that the bottom is full – you don’t need to fill the whole thing. Finally, wait!

You’ll notice after a few minutes that a cloud begins to form in the jar and water begins to condense on the sides. This is exactly how fog forms! The water at the bottom represents warm, moist air at the surface of the Earth. The ice cubes represent cooler air moving over the warm surface. The reaction between the warm, moist air and the cooler air cause the moisture in the air to condense and form a cloud at the surface – fog!