Press and hold the recirculation button. Then press the
temperature up ("+") button to switch between degrees Celsius & Fahrenheit on the Climate Control Temperature and Instrument Panel Outside Temperature
Cluster is set up for Canadian usage, easily determined by using the Tech 2 and entering cluster data and scrolling to English/metric. If the cluster data displays metric the cluster must be exchanged, replaced.
You can try taking a look at your owners manual, there may be a procedure in there. If not you may need to go to a dealership. That bulletin I posted up sounds like a tech2 is needed to scroll threw the options.
kindda dumb and not sure if it will work, but do you have a DIC (drivers information center) in your car? I beleive you can go into that and change setting from metric to english..so from Celsius to Fahrenheit