Cumulus clouds are comprised of water droplets, water vapor, super-cooled water droplets and ice crystals (when the freezing point is in the middle of the cloud), according to Northern Michigan University. Cumulus clouds are the most recognizable because they appear light and fluffy like cotton balls.
Cumulus clouds only have a lifetime of approximately 5 to 40 minutes. They are known for their flat bases and lumpy top outlines. This type of cloud is most often associated with fair weather, but cumulus clouds can cause short and heavy rainfalls. They are formed by frontal lifting or the rising of warm air, which cools and then condenses.