From Middle English widren, wydderen, related to or perhaps an alteration of Middle English wederen ("to expose to weather"), from Old English wederian ("to expose to weather, exhibit a change of weather").
From Proto-Germanic: Dutch verwederen, Dutch verweren ("to erode by weather"), German verwittern ("to be ruined by weather; to erode")
From Middle English wither, from Old English wiþer, from Proto-West Germanic *wiþr.
From Proto-Germanic: Low German wedder ("against"), Dutch weer ("again, back"), German wider ("against, contrary to"), German wieder ("again"), Gothic 𐍅𐌹𐌸𐍂𐌰, Old Norse viðr.