High clouds

Identifying cirrus, cirrocumulus and cirrostratus clouds. All high-level clouds - where the base is above 20,000 ft - are a type of cirrus cloud.

Cirrus

Height of base: 18,000 - 40,000 ft

Latin: cirrus - lock or tuft of hair

Cirrus are short, detached, hair-like clouds found at high altitudes. These delicate clouds are wispy with a silky sheen or look like tufts of hair. In the day time, they are whiter than any other cloud in the sky. While the sun is setting or rising, they may take on the colours of the sunset.

Cirrus cloud Cirrus cloud

Cirrocumulus

Height of base: 20,000 - 40,000 ft

Latin: cirrus - lock or tuft of hair; cumulus - heap

Cirrocumulus clouds are lots of small white clouds - called cloudlets - grouped together at high levels. Composed almost entirely from ice crystals, the little cloudlets are regularly spaced, often arranged as ripples in the sky. They are relatively rare, and unlike altocumulus clouds, never have any shading.

Cirrocumulus cloud (Photo: Jane Corey) Cirrocumulus cloud (Photo: Jane Corey)

Cirrostratus

Height of base: 18,000 - 40,000 ft

Latin: cirrus - lock or tuft of hair; stratus - flattened or spread out

Cirrostratus are transparent high clouds covering large areas of the sky. They sometimes produce white or coloured rings, spots or arcs of light around the sun or moon that are known as halo phenomena. Sometimes they are so thin that the halo is the only indication that a cirrostratus cloud is in the sky.

Cirrostratus can span thousands of miles, and may be smooth or fibrous and are often fringed with cirrus clouds.

Shadows will normally still be cast by the sun when shining through cirrostratus clouds, which can help distinguish them from similar nimbostratus clouds.

Cirrostratus cloud (Photo: Matthew Clark) Cirrostratus cloud (Photo: Matthew Clark)

For more detailed information on cloud spotting and pictures of different types of clouds, view our Cloud types for observers Cloud types for observers (PDF, 4 MB) guide.

Last updated: 31 May 2013

  • Low-level clouds
    Help with identifying low-level clouds - cumulus, cumulonimbus, stratocumulus and stratus.

  • Mid-level clouds
    Information on spotting medium-height clouds - altocumulus, altostratus and nimbostratus.

  • Other clouds
    Guide to observing other cloud phenomena including noctilucent night clouds and contrails.

  • Cloud spotting guide
    Use our cloud spotting guide and video to help identify different types of clouds in the sky.