What is cumulus?

Cumulus is a type of cloud that looks fluffy and white, like big cotton candy floating in the sky.

Imagine you're playing with a pile of marshmallows. You squish them together, then let them puff up again, that’s what cumulus clouds look like. They’re made of tiny water droplets or ice crystals that are floating high up in the air.

Cumulus clouds usually start on a sunny day when the air near the ground gets warm and begins to rise, just like hot air from a toaster. As this warm air goes up, it cools down, and the water vapor in it turns into tiny droplets, forming the fluffy shape of a cumulus cloud.

Sometimes, these clouds can grow bigger and taller, and then they might turn into something else, like storm clouds! But on a calm day, they’re just there to remind you that the sky is full of fun shapes.