fair weather vs temperateness

fair weather and temperateness both are nouns.

Word	Noun	Adjective	Verb	Adverb
fair weather	Yes	No	No	No
temperateness	Yes	No	No	No

As nouns, fair weather and temperateness are synonyms defined as:

fair weather and temperateness: moderate weather; suitable for outdoor activities

Other synonyms of fair weather include sunshine.

fair weather (noun)	temperateness (noun)
moderate weather; suitable for outdoor activities	exhibiting restraint imposed on the self
	moderate weather; suitable for outdoor activities