In the middle of July 107 degrees in Phoenix,. Your options to take a 3 year old are very very very limited. Eventually they will get sick of all outdoor activities. They will get sick of movies. Honestly where else can you take them? Children's Museum of Phoenix that is where.
Overall this place judged on it's own ain't bad. 11 bucks a person is a bit high. Now I am judging this place on it's price. Not on a free day or on another free way you can get in. There will be enough to keep your kid occupied till 4 pm when you leave. Make sure you bring a lunch or you will be spending typical high end corporate lunch room prices for their food area. Truth is. You will get a bit bored. But honestly this place is completely designed for the kids and for their point of view.
Now judging this place against other places in July in the Phoenix area. hahahaha. Where else are you going to take your kid? The Mall? A movie? A pool or waterpark? Good luck. Just take them to Children's Museum of Phoenix. They will have a blast.
P.S parking is free. Yipppppeeeeee