Cumulus clouds are a type of low-level cloud that can have
noticeable vertical development and clearly defined edges.
Cumulo- means "heap" or "pile" in Latin. They are often
described as "puffy" or "cotton-like" in appearance, and
generally have flat bases. Cumulus clouds, being low-stage
clouds, are generally less than 6,500 feet (2,000 m) in altitude
unless they are the more vertical cumulus congestus form.
Cumulus clouds may appear by themselves, in lines, or in
clusters. Cumulus clouds are often precursors of other types of
cloud, such as cumulonimbus, when influenced by weather factors
such as instability, moisture, and temperature gradient.
Normally, cumulus clouds produce little or no precipitation, but
they can grow into the precipitation-bearing congestus or
cumulonimbus clouds. Cumulus clouds can be formed from water
vapor, supercooled water droplets, or ice crystals, depending
upon the ambient temperature. They come in many distinct
subforms, and generally cool the earth by reflecting the
incoming