I have been there the past two Augusts. We were there the week after the 15th. It is hot but it was hotter in Jersey than in Florida.
There can be a lot of rain. We had a few afternoons of rain both times. Each time we had one afternoon where the rain was torential. What we did each time was put up a large tarp above the tents. We used ropes and stakes and the trees aroung the site. This kept the majority of the rain off the tents and we didn't have any problem.
The site will fit two large tents. Both times we set up two tents. The first August I went with another mother, my son and her three daughters. My neice joined us for a couple of days. The site also comes with a picnic table, water and electricity, which one time we used for those small box fans. My sons and I all now have battery operated fans but those cheap box fans and an extension cord works great and takes the edge off heat at night.
The bathrooms are great. They all have air conditioning and full showers. The laundry room is right there and so is a house phone. The ice machine is also by the rest station.
I personally like the 1500 loop especially the lower numbers. I have stayed in 1503 once and 1506 twice. They are near the rest station, and the bus stop. Across the road from the bus stop is the pool and past the pool is the Meadow Trading Post.
I think the end of AUgust is a perfect time if you can go then.
Don't forget that near the pool is the creek where you can canoe.
Have a great time
Dona