harshness vs inclemency

harshness and inclemency both are nouns.

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

As nouns, harshness and inclemency are synonyms defined as:

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

harshness (noun)	inclemency (noun)
the quality of being harsh or rough or grating to the senses	excessive sternness
excessive sternness	weather unsuitable for outdoor activities
the roughness of a substance that causes abrasions
the quality of being cruel and causing tension or annoyance