Cumulus
2,000 - 6,500 ft (600 - 2,000 m)
“I wandered lonely as a cloud that floats on high o'er vales and hills”— William Wordsworth
Cumulus clouds are the ones you drew as a child—puffy white cotton balls floating across a blue sky. They're the fair-weather companions, the clouds that make you want to lie in the grass and spot shapes in their billowing forms.
The name comes from the Latin word for "heap" or "pile," which is exactly what they look like: great heaps of cloud rising from flat bases. Each one is essentially a bubble of warm air that's risen from the heated ground below, cooling and condensing as it ascends.
On a typical sunny day, cumulus clouds grow throughout the morning as the sun heats the earth, reach their maximum size in the early afternoon, and then dissolve again as evening approaches. They're daily visitors, familiar and friendly.
things worth knowing
- A typical cumulus cloud weighs about 1.1 million pounds despite floating effortlessly
- The flat base marks the exact altitude where rising air cools enough for water vapour to condense
- All cumulus clouds in a given area tend to have their bases at the same altitude
- Fair weather cumulus are wider than they are tall; if they grow taller than wide, storms may develop
weather wisdom
Fair weather; larger cumulus can develop into rain-producing clouds