It's not that unbelievable. Its the normal temps of that card under full load. If its on idle then you're in trouble.
You could improve that temps by arranging the innards of your case so that you would have a clear passageway for air. Try to accomplish a good airflow inside the case. You could also dust the card, put some AS5 in it, and reseat the cooler. It would give you quite a drop in temps.