Southeast AZ is very bipolar at the moment. We've had several 29 degree mornings with frost on the windshield, and several 80+ degree afternoons, all within the past week or so.
Can't say a a 50 degree morning-afternoon delta is unheard of around here. Then again, I can't say I've ever gotten used to it either. Heavy coat in the morning, T-shirt 8 hours later.