how far from the earth are the clouds
The categories are simple - low clouds, middle clouds, and high clouds. Low clouds can have a base from the ground up to about 6,500 feet. Some clouds in this category include cumulus, cumulonimbus, and stratus clouds. Middle clouds can have a base ranging from about 6,500 ft to about 20,000 feet up. Some clouds in this category include altocumulus, altostratus, and nimbostratus.
Clouds are defined by both the way they look and how high they are in the atmosphere. For example, cirro (meaning wisp of hair) is a prefix given to high-altitude clouds (above 20,000 feet). Alto (meaning high) is a prefix given to mid-altitude clouds (between 6,000 and 20,000 feet).
High clouds (Family A) These generally form above 16,500 feet (5,000 m), in the cold region of the troposphere. In Polar regions, they may form as low as 10,000 ft (3,048 m); they are denoted by the prefix cirro- or cirrus. At this altitude, water frequently freezes so clouds are composed of ice crystals.