Camping in Idyllwild is great in the summer. Because it's at about 6000ft in elevation, the place stays relatively cool. While we were there in July the high was in the low 80's. Plus, the place is only about 2 hours away from Los Angeles, but you'll like you're much further away with the awesome green scenary up there.

We camped at the main state park, and found campsite situated relatively close to some structures, including a basketball court and swimming pool. Aside from having to hear kids playing basketball all morning and evening (who I think were attending a retreat), the campsite was convenient and nice.

We hiked up to the lookout tower (Tahquitz Point), which provides an amazing view of the entire area. The elevation gain is about 1700ft, so it was a good workout.