We've had a beautiful weekend here, sunny, in the 60s. My fiance Mark claims that mid-September to mid-October is the best time of year to visit New York. (It helps that his birthday is in mid-October).
So far, Mark has been right. It feels like late Spring, and people are eating and drinking outside. The light quality is incredible, sort of a golden color, perfect for taking photos.
Related posts: On Art and Music, Below Times Square, Halloween Musicians and the NYC Marathon and Tompkins Square Park, in Alphabet City.