aridness vs aridity

aridness and aridity both are nouns.

Word	Noun	Adjective	Verb	Adverb
aridness	Yes	No	No	No
aridity	Yes	No	No	No

As nouns, aridness and aridity are synonyms defined as:

aridness and aridity: a deficiency of moisture (especially when resulting from a permanent absence of rainfall)

Other synonyms of aridness include thirstiness.

aridness (noun)	aridity (noun)
a deficiency of moisture (especially when resulting from a permanent absence of rainfall)	the quality of yielding nothing of value
	a deficiency of moisture (especially when resulting from a permanent absence of rainfall)