Where in Phoenix will you be and what time of day are you able to run? Morning is by far the best as the evening temps don’t get much below 100 until after 9pm currently. By early morning I’m talking 5am because even by 7am you’ll be searching for shade.
The bridal path on Central offers good shade but it’s only a bit over 3 miles total in length. If you have access to Scottsdale then north on the canal from Camelback gets evening shade and you can continue up the green belt on Hayden to stretch it out longer for more shade too. Added bonus, there’s plenty of water stops on the way as well so you don’t have to lug a bottle or two.
I’d avoid camelback unless you’re a Walmsley type because of the aforementioned comment on its grade and it’s a cluster f of hobby Instagram “hikers”. Squaw Peak is the same. If you are really dying for an uphill run like that then I’d head over to South Mountain and run the road up to the towers. San Juan road is another good one for more of a rolling route but neither of them offer any shade so hit it in the morning.
If you’re just wanting something flat that you can cruise and you can get out early nothing beats the canal through old town Scottsdale and into Phoenix. You can string 24+ together on that pretty easily and again, there’s water stops along the way if you have some local knowledge which I’d be happy to share.
Lastly, I’d be happy to show you some routes if that jives for you and times/paces match up.
Any other questions just post me up and I’ll try to check back in. I’m in uptown Phoenix and run the canal daily. Matter of fact, I need to get on that thing this evening once the sun sets.