Hello, desert vdog here, same round about area you speak of, and exact same environment. The summers indoors are awful! To be honest, if you can, get a mountain bike, quad, offroad golf cart, or dune buggy. Get you a couple hardenend clones and go play in the desert. You know as well as I do that there is plenty of places out there. Joe Pesci quote from Casino "theres a lot of holes out in that desert" ofcourse he meant final resting spots.
As far as indoors, the best I did one summer, was keep the central air down to 72 degrees (in the house), and then overpowered my 400 w with a 440 cfm can fan, ejecting the hot bulb air into the attic. Doing it in a garage is going to be way hard, I know how it gets, when its 117 outside, the garage can be 128, seriously, and then add a bulb.... forget about it (more mobster slang). I saw a really really cool article in a skunk magazine, where the guy had framed a 8x8x8 in his garage, sheet rocked it, insulated it, and then hung a 12000 btu window unit thru the side with the exhaust also going out of the garage. He pulled the whole summer with it in Las Vegas and the temps were 72 -78 degrees inside his constructed garage room. I know that might be to much to ask, but man, not trying to kick your shins or demotivate you, but a garage grow in our neck of the woods in July, whoa! Good luck, thats the trade I guess we get, short indoor season for a long outdoor. I have smoked some of the best outdoor homegrown from bagseed in the desert, no lie.
Monsoon season, can be hard on plants, but not wipe them out, since there are usually only a handful of real bad rains, and mold is never an issue, because even with a front blowing in or out the humidity is still only 20%. Thats whats indicative of monsoons, real explosive and real quick, but then they go away, and things dry out really really quickly. The bigger issue and concern is getting water to your plants on a regular basis when its dry. I also saw in a magazine, where a guy watered one plant every third day during the hot months and another plant once a week, both came from same mother. The heavier watered plant yielded 22 ounces while the less watered yielded 8. Like you said you might have to keep a smaller batch with less lights and a ton of a/c during june july august. Not saying people dont grow successfully indoors in the southwest, but it takes ALOT of venting and conditioning of air.
P.S. if you play outdoors, look at afghani, I have heard that pure indicas sweat with resin in the high heat summers.
