inclemency vs severeness

inclemency and severeness both are nouns.

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

As nouns, inclemency and severeness are synonyms defined as:

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

inclemency (noun)	severeness (noun)
excessive sternness	extreme plainness
weather unsuitable for outdoor activities	excessive sternness
	something hard to endure
	used of the degree of something undesirable e.g. pain or weather