sunniness

from WordNet (r) 3.0 (2006)

sunniness
    n 1: lightness created by sunlight
    2: the quality of being cheerful and dispelling gloom; "flowers
       added a note of cheerfulness to the drab room" [syn:
       {cheerfulness}, {cheer}, {sunniness}, {sunshine}] [ant:
       {uncheerfulness}]

from The Collaborative International Dictionary of English v.0.48

Sunniness \Sun"ni*ness\, n.
   The quality or state of being sunny.
   [1913 Webster]