hardness vs inclemency

hardness and inclemency both are nouns.

Word	Noun	Adjective	Verb	Adverb
hardness	Yes	No	No	No
inclemency	Yes	No	No	No

As nouns, hardness and inclemency are synonyms defined as:

Other synonyms of hardness include harshness, rigor, rigorousness, rigour, rigourousness, severeness, severity, stiffness.

hardness (noun)	inclemency (noun)
a quality of water that contains dissolved mineral salts that prevent soap from lathering	excessive sternness
the property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale	weather unsuitable for outdoor activities
the quality of being difficult to do
devoid of passion or feeling; hardheartedness
excessive sternness