I moved to the west suburbs of Phoenix a couple years ago. I hate the summer heat but like Gayle said, 8 or 9 months of the year is fine. Right now it is just about perfect. Still in the high 80s or low 90s during the day but the evenings & mornings are just perfect.
The only way to tolerate the heat is to stay inside when it's so hot. A few weeks ago I went about 1 1/2 hrs north to Prescott & Prescott Valley. It's much cooler up that way and a perfect get away from the heat. Sedona was good too. Haven't made it to Flagstaff yet.
I lived in Houston (Clear Lake area) for about 6 years until 2005 and loved being able to go down to Galveston and walk or ride my bike on the seawall. I certainly can't get out and ride my bike here in the desert in the summer time. The first winter I was here we had a short very cold spell that killed a lot of the plants. I hear that is very unusual.
Haven't seen the black widow spiders or rattle snakes - neighbors have had both in their yards. We have found two scorpions inside the house. The first one freaked me out and I was up all night on the computer trying to find out how to get rid of them. Since then, I went on a scorpion hunt one night up at Lake Pleasant (NW of Phoenix). Hundreds of those critters all along the trail that night!!! They really do glow in the dark under a black light.
There are also frogs that can kill dogs. So far one dog has died and another injured by biting on the frogs in this community. And don't forget the tarantulas. Saw one in the grocery store parking lot the first fall I was here.
The coyotes come through our community all the time. Love to hear them howling at night. The night skies are beautiful too - saw falling stars the last two nights.