The fraction of the sky covered by clouds, expressed in oktas (eighths) or percent.
basicWhat is Cloud Cover?
Cloud cover is reported in oktas: 0 = clear sky, 4 = half covered, 8 = completely overcast. Automated weather stations use ceilometers to measure cloud base height. High cloud cover reduces solar radiation during the day but traps heat at night.
Key points
- The fraction of the sky covered by clouds, expressed in oktas (eighths) or percent.
- Category: basic
Related terms
See also: cloud-cover is connected to other weather concepts. Browse the full glossary for related definitions.