cloudlessness

from WordNet (r) 3.0 (2006)

cloudlessness
    n 1: the lightness of a sunny day when there are no clouds in
         the sky

from The Collaborative International Dictionary of English v.0.48

Cloudless \Cloud"less\, a.
   Without a cloud; clear; bright.
   [1913 Webster]

         A cloudless winter sky.                  --Bankroft.
   -- {Cloud"less*ly}, adv. -- {Cloud"less*ness}, n.
   [1913 Webster]