cheerfulness vs sunniness

cheerfulness and sunniness both are nouns.

Word	Noun	Adjective	Verb	Adverb
cheerfulness	Yes	No	No	No
sunniness	Yes	No	No	No

As nouns, cheerfulness and sunniness are synonyms defined as:

cheerfulness and sunniness: the quality of being cheerful and dispelling gloom

Other synonyms of cheerfulness include cheer, sunshine.

cheerfulness (noun)	sunniness (noun)
the quality of being cheerful and dispelling gloom	lightness created by sunlight
a feeling of spontaneous good spirits	the quality of being cheerful and dispelling gloom