inclemency vs rigorousness

inclemency and rigorousness both are nouns.

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

As nouns, inclemency and rigorousness are synonyms defined as:

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

inclemency (noun)	rigorousness (noun)
excessive sternness	something hard to endure
weather unsuitable for outdoor activities	excessive sternness