I live in Atlanta and have fine, naturally straight, super blond hair that I didn't know could frizz until I moved to The South. Just used this on a humid, humid morning in the 80s here and my hair looks SHINEY and after 6 hours it is still as smooth as the moment I finished drying it and I was out and about at lunch! And.....I didn't even use my brush when I dried it and it cut the drying time in HALf if not more. BUY, BUY, BUY!!! (I am not a professional stylist--just an average consumer)