Clouds can be a way to help set the tone of a world, especially so in worlds that are primarily visual. Different cloud types can have a large impact on any world that features a sky, and in worlds where air-travel is common or a central component clouds can be vital.

Cirrus

Filamentous clouds that are usually white in color though during sunrise and sunset will glow yellow or red. Cirrus clouds are composed of small ice crystals

Cirrocumulus

Small thin patches of white clouds that seem to form grain or ripple-like patterns. These clouds are uncommon.

Cirrostratus

Fibrous or hair-like clouds. These clouds can be extensive and nearly cover the entire sky.

Altocumulus

White or grey with rolls or rounded masses. These are the most common type of mid-altitude cloud.

Altostratus

Grey or bluish sheets of clouds that will only partially obscure the sun.

Nimbostratus

Results from a thickening of altostratus clouds and can entirely obscure the sun. Dark and grey. Can be host to heavy rain or snow. During precipitation the base of these clouds can descend to lower altitudes creating an extensive vertical cloud.

Cumulus

Dense, individual, white clouds with darker flat bottoms. These usually form on otherwise clear days. Can form mounds, towers, and domes.

Cumulonimbus

A massive thunderstorm cloud. These are dense clouds that form huge towers. Can also produce hail and tornadoes.

Stratocumulus

White or grey clouds that form in a lattice-like sheet.

Stratus

A grey cloud layer with a uniform base.

Asperitas

Rolling waves in the base of clouds.

Fog

A cloud that has descended to rest on the ground.

Mammatus

An ‘upside-down’ cloud with the cloud sinking down into a pocket of drier air. Mammatus clouds are associated with thunderstorms and severe weather but are not always linked.