Source : Webster's Revised Unabridged Dictionary (1913)

Cloudiness \Cloud"i*ness\, n.
   The state of being cloudy.

Source : WordNet®

cloudiness
     n 1: the quality of being cloudy [syn: {murkiness}, {muddiness}]
     2: the state of the sky when it is covered by clouds [syn: {cloud
        cover}, {overcast}]
     3: gloomy semidarkness caused by cloud cover [syn: {overcast}]