Home / Cloud Types / High-level Clouds

High-level clouds are in the cold region of the troposphere. However, in Polar regions, they may form as low as 10,000 ft (3,048 m). They are denoted by the prefix cirro- or cirrus. At this altitude, water almost always freezes so clouds are composed of ice crystals. The clouds tend to be wispy, and are often transparent.

• Cirrus
• Cirrus uncinus
• Cirrus Kelvin-Helmholtz colombia
• Cirrostratus
• Cirrocumulus
• Pileus
• Contrail, a long thin cloud which develops as the result of the passage of an aircraft at high altitudes.