I've done a drop camp in the 'Flat-tops' during the first season, but never the second. EKM is right on, you can have beautiful days or you can have a blizzard so you have to go prepared for both. I don't think I'd count on 'hot' weather that time of year at 10.5. Might get warm but I've not seen it hot. Plus, you can get alot of snow in a short period of time which can make getting out an adventure. Depending on your outfitter, I've seen one who wouldn't bring the horses in due to the snow. The flat-tops is a beautiful area and we almostalways hunted at the treeline. Lots of elk, and lots of quiet. Good luck, you're gonna love it.