How to Make a Cloud Rain in a Jar

Now that school is back in session, I’m back working on my weather experiments for kids! This blog will explain how to make a cloud in a jar ☁️ and then make that cloud rain ☔️. You can see a video demonstration at the end of this post and it will also be on my IGTV on Instagram (@weatherstrong).

Here’s what you need:

• Glass jar

• Paper plate or paper bowl

• Ice

• Hot water 

Here’s what you do:

• Fill the jar half way with hot water. You can heat some on the stove or get it out of your coffee maker. If you’re doing this with kids, the adult should handle the hot water because the jar gets hot quickly. 

• Place the paper plate on top of the jar and notice what happens. You should see a cloud start to form in the top of the jar. The water vapor is collecting at the top of the space. Because it’s so warm, some of the liquid water evaporates into vapor. Since the warmest air rises, the water vapor collects at the top of the space.

• Put ice on the plate. I left my ice cubes inside the plastic bag to avoid a mess later and it worked just as well as having them loose. Depending on how much ice you use (I have 12 large cubes here), this next part may take several seconds or several minutes to start. You will notice water drops starting to form inside the glass. That’s condensation – water vapor cooling and condensing back into liquid water. The ice is cooling the water vapor that collected at the top of the jar. Shortly you will see those water drops collecting together and starting to fall down the sides of the jar. This is also how rain forms in clouds. It condenses and collects into larger droplets until they are too big and heavy for the cloud to hold anymore. Then they fall to the ground.

Application: 

This teaches us about evaporation, condensation, precipitation, and the water cycle. As always, if you have questions, you can get a hold of me using the contact form right here on my website!