We have gone 6 times during Sept and just love it due to the lack of crowds. However, it is HOT/Humid and usually rains once per day for 15 minutes, but we haven't been affected by this. Our strategy is to go out to parks early, back to on-site hotel early afternoon to nap or swim and then head back out to parks or dinner around 4-5pm (kids are now 8 & 5, so they're not really into napping, but love to swim!). This really works for us, but we make sure we take extra T-shirts as we usually change them twice a day and take hats and lots of sunscreen! I think crowds pick up a bit in Oct due to a lot of conferences that take place that month, but its generally a lot less crowded than other times of year. Just avoid the holiday timing in Oct.