I was told that there is law in AZ that I can leave my dog in my car at anytime of the year. Even if it is 50 degrees out and the windows are open. Is this true?

No do not leave your pet in any vehicle at anytime cause the law will be notified immediately as soon as someone notices your pet in a vehicle.

Definitely not...

I know for a fact that your not allowed to leave them in a vehicle in summer or out side ur house. You will be fined for animal cruelty or negligence. If I were you I would not do it. No matter what weather we have here in Az. Your pets are important take care of them as you would with a human, they take care of us.