We've been during late November twice. In '98 it was low 60's at night and upper 70's to low 80's during the day. Great week.
In '99, however, we froze. A few mornings and nights it dropped into the mid 40's and we froze ! It did rise to upper 60's on those days. I'd pack at least one pair of jeans/sweat pants and a jacket just in case. We've even experienced chilly temps (40's at night/morning) in early November. Usually the afternoons are warm, but not necessarily swimming weather. I've seen highs of only upper 60's to highs of upper 80's in Nov.
Have a great trip.