How is cloud cover measured?

Cloud cover is measured in oktas, which represents the fraction of the sky that is covered by clouds. Each okta corresponds to an eighth of the sky's dome; therefore, a completely clear sky would be 0 oktas, and a fully overcast sky would be 8 oktas. This method provides a standardized way to quantify cloud presence and is widely used in meteorology for reporting and analysis.

The other methods mentioned do not pertain to measuring cloud cover directly. For instance, meters above sea level would apply to altitude or elevation measurements, degrees of temperature relate to thermal conditions rather than cloud extent, and millimeters of precipitation measure rainfall or liquid water accumulation rather than the presence of clouds in the sky. Understanding how cloud cover is quantified is essential for accurate weather reporting and forecasting.