Last year, late October was still summer-like, with temps in the mid and high 90's. I wore minimal clothing, light and breathable. It was almost too hot to enjoy the pool. While that's luckily not on the current forecast, be aware it's still possible.
Another year it was mid 70's and raining, so that's possible too. In that type of weather I don't like to be too covered up either, as you can get sort of sticky feeling. A light jacket should suffice.
In my opinion, it does not get chilly at night in the fall the same way it does in the spring. I still bring some long pants and a sweater, but they are seldom needed. Not scare you about the odd weather though, short sleeved shirt/tank top/dress and shorts/skirt are usually fine. Hopefully we will just be getting the normal beautiful weather (I'll be there too) in the comfortable 80's! And yes, perfect pool temps!