Cirrus – high wispy cloud made of ice crystals: 13,000 – 40,000ft (4,000m – 12,000m)

Cirrocumulus – high puffy cloud that contains supercooled water droplets: 16,000 to 39,000 ft (5,000m – 12,000m)

Cirrostratus – high, very-thin stratiform cloud composed of ice crystals: 20,000 to 43,000ft (6,000m – 13,000m)

Altocumulus – middle altitude, globular and fluffy cloud that often occupies layers or patches: 7,000ft – 23,000ft (2,000m – 7,000m)

Altostratus – middle altitude, sheet-like cloud comprised of water droplets and/or ice crystals: 6,500ft – 20,000ft (2,000m – 6,000m)

Cumulonimbus – a towering, vertical cloud made of water vapor that begins at low altitudes and can reach the tropopause, often causing a storm: 2,000ft – 52,000ft (500m – 16,000m)

Cumulus – low clouds that have a flat base and appear as ‘heaps’, puffy and are largely the quintessential cloud: 1,000ft – 6,600ft (200m – 2000m)

Stratus – low, mainly horizontal clouds that tend to have a flat and uniform base and can be best described as hazy, continuous sheets occurring very near the Earth’s surface. It is called fog when it makes contact with the Earth’s surface: 0ft – 7,000ft (0m – 2000m)

Nimbostratus – a multilevel, uniform, dark gray cloud that usually produces precipitation without thunder or lightning: 2,000ft – 18,000ft (500m – 5,500m)

Stratocumulus – low, like Altocumulus but at a lower altitude and is associated with large, dark, and round heaps: 2,000ft – 7000ft (500m – 2000m)

Fractus – low, small, very irregular cloud fragments that are associated with larger cloud formations having formed near or broken off from them. They can trail behind or ride ahead of larger clouds, i.e. scud clouds: 2,500ft – 5000ft (750m to 1500m)