Ghosts chasing Audi

Its 85 degrees outside and my air conditioning turns itself off. I check the dash and the ambient temperature readout says its -24 degrees F., and dropping! Roll down window and check- still hot out. Everything else normal. Over the next 10 to 15 minutes it goes down to 54 below zero, then starts climbing. When it get back to 40 or 50 degrees the air conditioner comes back on.

Started a month ago, doing it once or twice a week. Now every day. Temp sensor?