My 2005 Prius Air Conditioning Stopped Working For A Couple Of Minutes

I started my 2005 Prius (79,400 miles) and the A/C system did not come on. I tried various setting on the touch screen and nothing happened. I turned the car off and restarted it. On the third restart the A/C system worked normally. I'm in Dallas, TX so the climate control system is generally on A/C. About a month ago this started: I would start the car, the A/C would come on, drop down in fan speed briefly and then work normally. Yesterday was the first time that the climate control system didn't come on at all. Is it a sensor? Does the climate control system have its own controller? Has anyone fixed this issue before? Thanks!