The Prius loves 100 F weather. I'm milking this thing. Usually get about 55 mpg on a tank. I'm at 70.2 mpg and ~350 miles. No AC, no fan, yes radio, no hard acceleration, yes 5 mph under the limit, nothing over 60mph. I'm going for a 70mpg/700 mile tank. Then I'll go back to AC and the speed limit on the next tank.
Ooops - Posted on the wrong site. This is a 2010. My wife drives the PiP. Altogether, we visit the gas station once per month each. But maybe it is good to post here to let potential PiP buyers know what their other option is and how many mpg they can get with a non PiP
I live in the Phoenix area as well..for many years. When the high is a hundred it's tough to do windows at the hottest part of the day. I use windows mornings and evenings. Use AC afternoons. Good job on the tank btw. In summer weather my best is 61.4 dash/57.8 actual. I have around 450 miles on my current tank so far and dash reads 60.5. When I have people ride in my car it hurts my mpg since I have to run AC higher than I normally do and I dont p&g. That and short trips dip my average. I'm waiting for a little cooler weather to try a 60+ mpg tank where it will be comfortable not using AC at all. Looks like you are going to hit that easily this tank. Let us know how your mpg/miles driven when you fill up. Hopefully you will hit 700 miles. I've done 600 once but never more than that. Good luck!