into the wind vs upwind

into the wind is not an adjective while upwind is an adjective.

Word	Noun	Adjective	Verb	Adverb
into the wind	No	No	No	Yes
upwind	No	Yes	No	Yes

As adverbs, into the wind and upwind are synonyms defined as:

into the wind and upwind: in the direction opposite to the direction the wind is blowing

Other synonyms of into the wind include against the wind.

into the wind (adjective)	upwind (adjective)
	towards the side exposed to wind

into the wind (adverb)	upwind (adverb)
in the direction opposite to the direction the wind is blowing	in the direction opposite to the direction the wind is blowing
	away from the wind