Written and first recorded by Ruthann Friedman (1967).
Hit version by The Association (US #1 1967).
From the wiki: “‘Windy’ was written by Ruthann Friedman, a transplanted New Yorker who moved to Venice, California, where she hung out with the cream of L.A. Pop royalty – a 16-year-old sneaking into the Troubadour in the early ’60s and, then, an 18-year old starting to write and play her songs on the guitar, making friends with David Crosby, Van Dyke Parks, and Tandyn Almer, author of ‘Along Comes Mary’, another big hit for The Association. (It would be Parks who would introduce Friedman to The Association.)