Cloud Facts

Facts about clouds

Clouds are made up of many millions of miniscule water droplets which are formed when moist warm air rises up into the sky and is then cooled down. If the cloud is very cold it means that it is made up of ice crystals. It takes somewhere between a few minutes and 1 hour for a cloud to be created.
Cloud Classification
    In 1803 a classification of clouds was made up by Luke Howard (born 1772, died 1864) who used Latin words to describe their characteristics.
  • Cirrus - tufts or whisps
  • Stratus - a layer
  • Nimbus - rain bearing
  • Cumulus - a heap or pile
There are now a number of basic cloud types with names based on combinations of the above words, as well as the word 'alto' which is now being used to describe medium level cloud. These main cloud types can be placed into three different sections depending on their height from the ground.
Low clouds
    These are normally made up of water droplets and have a base under 2,000 metres.
  • Stratocumulus
  • Cumulus
  • Stratus
Medium clouds
    These are normally made up of water droplets and have a base somewhere between 2,000 and 7,000 metres.
  • Altocumulus
  • Nimbostratus
  • Altostratus
High clouds
    Usually made up of ice crystals, these have a base somewhere between 5,500 and 14,000 metres.
  • Cirrus
  • Cirrocumulus
  • Cirrostratus