Cloud Types

cumulus

Cumulus clouds form when warm air rises from the ground and its water vapour condenses.

💡 Did you know? Their flat base sits exactly where the rising air reaches its dew point.

cumulonimbus

The cumulonimbus is the only cloud that reaches through all three levels.

💡 Did you know? It can grow over 12 kilometres tall: far higher than Mount Everest.

cirrus

Cirrus clouds consist purely of ice crystals and never produce rain.

💡 Did you know? Their name comes from the Latin „cirrus“, meaning a lock of hair.

stratus

Stratus sits low and produces at most drizzle.

💡 Did you know? When a stratus cloud touches the ground, we simply call it fog.

nimbostratus

Nimbostratus is a thick, dark layer without any visible structure.

💡 Did you know? It is so dense that you cannot even guess where the sun is behind it.

altocumulus

Altocumulus forms regular rolls or patches at roughly 2 to 7 kilometres.

💡 Did you know? An old weather saying holds that a mackerel sky means rain by evening.

Luke Howard

The London pharmacist Luke Howard gave the clouds their Latin names.

💡 Did you know? Goethe was so taken with Howard's system that he dedicated several poems to him.

Latin

Cumulus means heap, stratus layer, cirrus lock of hair and nimbus rain cloud.

💡 Did you know? Because the names are Latin, clouds share the same scientific names worldwide.

rain

Only nimbostratus and cumulonimbus carry it: both precipitation clouds.

💡 Did you know? In Latin, „nimbus“ also meant the halo around a saint's head.

middle level

Alto clouds float roughly between 2 and 7 kilometres up.

💡 Did you know? Although the prefix comes from the Latin „altus“ (high), alto clouds are only the middle ones.

three

There are low, middle and high clouds.

💡 Did you know? The cumulonimbus breaks the system: it reaches through all three levels.

ten

The ten genera are further divided into species and varieties.

💡 Did you know? Altogether the International Cloud Atlas lists over a hundred cloud forms.

anvil

The anvil forms where rising air can go no higher at the tropopause.

💡 Did you know? The anvil shape shows from far away which way a storm is heading.

lenticular cloud

It forms in the crest of the air wave downwind of a mountain range.

💡 Did you know? Its sharp lens shape has caused plenty of UFO reports.

asperitas

Asperitas looks like a churning sea surface viewed from below.

💡 Did you know? It was the first new cloud form added in over fifty years.

noctilucent clouds

They consist of ice crystals in the mesosphere: the highest clouds of all.

💡 Did you know? They glow because they are so high that sunlight still reaches them long after dark on the ground.

contrails

Water vapour from the exhaust freezes instantly into ice crystals in the cold air.

💡 Did you know? If they linger, the upper air is humid: often a sign of an approaching low.