If you consider that I have a GTX 460 Gigabyte that goes at 65° in full load, it should not be a surprise that the 470 goes at 95°
The Idle though is a bit high I think!! My 460 goes in idle at 25°/30°.....are you sure that in your case you have an appropriate air circulation? Because in the summer your card will die!!!
You told that you measured the temps with the case opened.....well that's the first mistake! A good airflow goes good if wel done, and if the case is closed!!!
What is your fan predisposition?
For your card, you should have at least one front pulling in, one rear pulling out and at least one up pulling out...each one with a good CFM
Do you also have a good CPU cooler? because it will surely help to cool even the things around it (a hot CPU will heat the GPU too!!!)