From Wikipedia, the free encyclopedia
Jump to: navigation, search
For other uses, see Overcast (disambiguation).
A completely overcast sky in Mehamn, Norway

Overcast or overcast weather, as defined by the World Meteorological Organization, is the meteorological condition of clouds obscuring all of the sky.[1] Overcast, written as "OVC" in the METAR observation, is reported when the cloud cover is observed to equal eight oktas (eighths).[1]

Sometimes clouds can be different colors such as black or white, but the word usually refers to grey.[citation needed] In some cases, it can be impossible to see distinct borders of clouds or the sky may be covered by a single type of cloud, such as stratus and the whole sky will be a dull white.

Periods of overcast weather can range from a few hours to several days. Overcast weather can also affect people suffering from seasonal affective disorder.

The same weather, when observed by pilots, might be referred to as (an) undercast.[citation needed]

See also[edit]