Though we may marvel at a cloud’s beauty or speculate about its shape (Is it a puppy? Or a sailboat? No, it’s a racecar!), how many of us actually understand the relatively simple science behind the formation of clouds?

In short, a cloud is a formation of condensed water. Water vapor is carried upward by the air current, eventually condensing on particles of dust or ice to form a cloud. The clouds that these particles form can, of course, take on any number of shapes and sizes, and can be measured in anything from yards to miles.  

Clouds are categorized by their base height, and then are divided into sub-categories based on shape. Among the following names, you’ll notice some commonly occurring roots and words, including:  

• Cirrus, which means “tendril”
  
• Cumulus, which means “heap”
  
• Stratus, which means “to spread”
  
• Alto, means “high,” yet in singing represents the second-highest voice part
  

 “High” Clouds (located approximately 20,000 feet and higher)
Cirrus: Long, thin, and wispy or feather-like
Cirrocumulus: A large patch made up of many small, puffy cloudlets
Cirrostratus: Thin, white, and uniform in appearance; can cover the entire sky

“Middle” Clouds (located approximately 6,500 to 20,000 feet)
Altocumulus: A large patch characterized by wave-like patterns or repeating rounded masses
Altostratus: Gray and uniform in appearance  

“Low” Clouds (located up to approximately 6,500 feet)
Cumulus: Typically small or medium-sized and puffy in appearance
Stratus: A low-lying, uniform gray cloud cover  

Cumulonimbus clouds
These clouds, which are associated with thunderstorms, can stretch through all three levels and may have the appearance of a very tall cumulus cloud.  

Do you think you know your clouds now? If so, identify the following five types of clouds, and then scroll to the bottom of this page to check your answers.

(1)	(2)
(3)	(4)
(5)

Photos by Marc Chalufour (1, 2, 3); ISTOCK (4); Jerry and Marcy Monkman (5)

 

 

 

 

 

 

 

 

 

 

 

Answers: (1) = Cumulus; (2) = Cirrus; (3) = Altocumulus; (4) = Stratus; (5) = Cumulonimbus