Grand Canyon is coolish year round. Visit Flagstaff instead of Tucson if you’re a northerner and can’t stand the heat.
flew by light,sight seeing plane to the south rim on a side jaunt on a trip to Vegas in ‘05....it was November and pleasantly warm....though it had been cooler a day or so before we got there....spent a year mostly in Tucson, in 1975 and traveled up to Flagstaff a few times, along with other places on the Mogollon Rim....You can have Tucson and Phoenix in the Summer, but the winters are glorious in the Sonoran Desert...Saguaro Natl park, the Catalinas..the Santo Rita's.....gorgeous.