We went this exact week last year, and will be going the same week this year. We experienced low crowds and shorter wait times. As for weather, it was intermittent. Some days/most nights required hoodies. It also rained half the time. We only got one pool day in, the rest of the time was either too cool or overcast. I think our experience was unseasonably rainy, but the cool part is pretty typical - highs average in the 70s with lows averaging in the 60s. If it's cloudy to boot, it can get cool.