Are you a morning person?

As people mentioned Phoenix is HUGE, road conditions vary widely by area.

I grew up in Tucson. Arizona is fine for cycling. During the summer, you're going to want to be finished with your ride by 8am. The temperature will drop by 30-40 deg at night, but since the high is 110F, you're only down in the 60-70 range by the time the sun comes up. Keep in mind that 110F is the temperature in the shade, not on an asphalt road which will be 120+. Staying hydrated is the major challenge.

November to March are great. You should be able to bike daily with comfortable temperatures. There's a reason everyone from Minnesota moves down there.