Agree with what's posted, also note it is very open, not much protection from wind and sun. Even in October you may put on some sunblock. At least it won't be too hot, but I've been in late September and it was pretty toasty in the afternoon. The upside of the wind and sun is that it dries fast after a rain. A light rain won't spoil your weekend.
Note "Switchgrass Campground" is the one near the official trailhead and most commonly used. The bathrooms are closed as noted, I wish they kept them open into October. We're joining the LMBC group the weekend of the 23rd this month. I like that as it is late enough to be cooler but bathrooms are still open. Enjoy!