south wind vs southerly

south wind and southerly both are nouns.

Word	Noun	Adjective	Verb	Adverb
south wind	Yes	No	No	No
southerly	Yes	Yes	No	Yes

As nouns, south wind and southerly are synonyms defined as:

Other synonyms of south wind include souther.

south wind (noun)	southerly (noun)
a wind from the south	a wind from the south

south wind (adjective)	southerly (adjective)
	from the south; used especially of wind
	situated in or oriented toward the south

south wind (adverb)	southerly (adverb)
	from the south
	toward the south