Cirrus Clouds: High, Wispy Streaks

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Definition: High-altitude, thin, and wispy cloud streaks composed of ice crystals

Description & Characteristics. Cirrus clouds have a distinct look relative to the other nine cloud types. Because cirrus clouds are made of ice crystals, they look different than your typical puffy cloud shape, and can take on a number of different forms that resemble spider webs, fish skeletons, mares’ tail, or hair-like commas. If you’re observing a cloud that’s fibrous in nature, there’s a strong chance you’re looking at a cirrus cloud.

But all cirrus clouds don’t have that distinctive, fibrous shape. They can also be found clumped together (cirrus spissatus), be entangled (cirrus intortus), and can look not quite as majestic when you spot them closer to the horizon. Because of their ice crystal composition, cirrus clouds are also capable of various optical phenomena such as sun dogs and cloud iridescence.

Though human-formed, condensation trails from aircraft can become cirrus clouds in the technical sense (cirrus homogenitus), created as a result of jet exhaust in cold temperatures found in the upper parts of the troposphere.

Cirrus uncinus (Ci unc), Cirrus floccus (Ci flo)
Cirrus fibratus (Ci fib), Cirrus floccus (Ci flo)
Cirrus floccus radiatus (Ci flo ra)
Cirrus fibratus radiatus (Ci fib ra)
Cirrus homogenitus (Ci hogen)
Cirrus spissatus (Ci spi)
Cirrus uncinus (Ci unc)
Cirrus fibratus (Ci fib)
A photograph of cirrus uncinus clouds (Ci unc) and cirrus floccus (Ci flo) over some trees

Cirrus Cloud Facts

  • Cloud Level (Étage): ….. High
  • Altitude/Height: ……… 5-15km (16,000-49,000 ft)
  • Latin Term: …………… Derives from cirro-, meaning curl
  • Abbreviation: ………… Cirrus can be abbreviated as Ci
A bar graph showing the visual color of a cirrus cloud

Cloud Color

White to light gray

A bar graph showing the precipitation potential of a cirrus cloud

Precipitation Potential


A bar graph showing the amount of sky cover from a cirrus cloud

Sky Cover

Mostly sunny to sunny

A bar graph showing how common observing a cirrus cloud might be

Cloud Frequency

Very common

Cirrus Cloud Species

Cirrus clouds have five associated cloud species: castellanus, fibratus, floccus, spissatus, and uncinus. The species spissatus and uncinus are unique to cirrus clouds.

A graphical illustration of a cirrus castellanus cloud

Cirrus castellanus

Rising towers, turrets

A graphical illustration of a cirrus fibratus cloud

Cirrus fibratus

Fiberlike, hairlike

A graphical illustration of a cirrus floccus cloud

Cirrus floccus

Puffy, ragged tufts

A graphical illustration of a cirrus spissatus cloud

Cirrus spissatus

Packed tightly, dense

A graphical illustration of a cirrus uncinus cloud

Cirrus uncinus

Curved, comma-shaped

Cirrus Cloud Varieties

Cirrus clouds have four associated cloud varieties: duplicatus, intortus, radiatus, and vertebratus. The varieties intortus and vertebratus are unique to cirrus clouds.

A graphical illustration of a cirrus duplicatus cloud

Cirrus duplicatus


A graphical illustration of a cirrus intortus cloud

Cirrus intortus

Interlaced, entangled

A graphical illustration of a cirrus radiatus cloud

Cirrus radiatus

Parallel bands and strips

A graphical illustration of a cirrus vertebratus cloud

Cirrus vertebratus

Fishbone-like, resembling ribs

Cirrus Cloud Supplementary Features

Cirrus clouds have two associated supplementary features: fluctus and mamma.

A graphical illustration of a cirrus fluctus cloud

Cirrus fluctus

Kelvin-Helmholtz waves, curls

A graphical illustration of a cirrus mamma cloud

Cirrus mamma

Sac-like, resembling cow udders

Cirrus Cloud Accessories & Other Clouds

Cirrus clouds don’t have any associated accessory clouds, but do have two other clouds associated with the cloud type: homogenitus and homomutatus.

A graphical illustration of a cirrus homogenitus cloud

Cirrus homogenitus

Caused by human activity

A graphical illustration of a cirrus homomutatus cloud

Cirrus homomutatus

Mutated from a homogenitus

Similar Cloud Types

Cirrus vs. Cirrocumulus

Both cirrus and cirrocumulus clouds are found at the same altitude, and a lot of times when observing cirrocumulus clouds, you’ll see cirrus clouds in close proximation. The biggest difference between the two is cirrocumulus clouds contain puffy cloudlets and look like grains of rice, where cirrus clouds are more fibrous, hair-like, or wispy in nature.

Cirrus vs. Cirrostratus

Cirrus and cirrostratus clouds are found at the same altitude and both can be fibrous in nature. When deciding between the two, remember that a cirrostratus cloud generally covers the sky and is more of a pale, veil-like layer cloud, where you’ll generally see more individual elements in a cirrus cloud, such as comma shapes, fishbone-like shapes, and other wispy shapes.