Set the fraction of the horizontal sky area which is covered by clouds.  

ic_cloudcover value

 
When a cloud cover is specified, the result will be calculated by the independent pixel approximation (IPA), that is, as weighted average of cloudless sky and overcast sky, where the cloud properties are taken from ic_file, etc. Please note that, if both wc_cloudcover and ic_cloudcover are set, both must be equal.

This option is ignored, if the option cloud_fraction_file is used.