In addition to the ten cloud types and fifteen cloud species, there are a total of nine cloud varieties. Cloud varieties go beyond the cloud type and species to better describe a cloud. While cloud types can only have up to one associated species, they can have multiple cloud varieties applied to them.
For example, stratocumulus stratiformis opacus describes a stratocumulus cloud which has a horizontal layer-like form (stratiformis) that is dark to the point where it blocks out the sun (opacus). Altocumulus perlucidus translucidus describes an altocumulus cloud that is transparent by small gaps (perlucidus) that is thin enough where the sun is shining through (translucidus).
Illustrated below are the nine cloud varieties. Clicking on the cloud illustrations below will lead you to a page that will provide you with a description, photograph examples, and illustrations of each cloud variety. Each illustration includes the cloud type (abbr.) that the variety can be associated with. The orange dot under the cloud type abbreviation indicates the specific cloud type that’s portrayed in the illustration. When applying a variety of cloud to a cloud type that you’re identifying, choose the cloud varieties that best describes the cloud you’re observing. ⛅