Well having lived here in central Phx since the 80's you just are NOT going to get alot of interest untill the evening temps come down. Even a Sat am meet up is HOT right now :)
I would say your best bet is to mark a date in Sept when it cools off a little....
There are lots of great trails around Phx within an hour, the Funtreks & Backcountry Discovery books are a good start along with Trailsoff Road, OnX and other digital resources.
This is the time of year we escape every weekend possible to higher elevations, maybe a Payson or Showlow meetup on a Sat for something easy like a Rim Road run.