Stating the obvious seems the only way to adequately begin this post: Moab is hot in July! If I was to hazard a guess I would also say that Moab is hot ALL summer. After that profound statement I will say you may want to visit during another season. It is, however, a pretty spectacular destination.
We went on more hikes than at any other destination thus far. We quickly discovered that the best time to hike was early morning before the heat effectively drove you indoors or to the pool. Dead Horse Point State Park and Delicate Arch and the Windows at Arches National Park were our favorite hikes.
In the evening when it cooled off we ventured to downtown Moab. One evening we found a handful of locals and a bluegrass band hosting an outdoor concert in what essentially was a yard right off Main Street. We decided they were "our people" when the band coincidentally began playing Bob Will's Take Me Back To Tulsa right after we arrived.
The following day we visited an outdoor dinosaur themed museum called Moab Giants and went in search of fossil souvenirs at a road-side rock shop. That was the extent of our desert in July activities. I should say though that no further activities were required. Moab is the kind of destination that need not boast any entertainments other than that which nature provides. The vast parks with their canyons and arches are truly unique and beautiful! I will go back again... in the winter!