I plan on taking mine outside once he arrives, what is the maximum outside temperature I can take him out in? Here in Arizona it can get to 110 during the summer which obviously is too hot, but what about when it's 95 out or 90?
I'm in south Texas we average 100-105 for our summers and I leave mine offside 24/7. I cool mine off with a outdoor porch misting system that goes off every 1 1 1/2-2 hours for 15-30mins and they seem to do just fine. Plus they have 3 hibiscus to get shade from and I hose them down with the garden hose I've never caught them sitting around with their mouth open. They seem to love it out there.
I think the temperatures you mention are not really a problem. Just make sure you provide enough shade and give them lots of opportunities to drink. Being hydrated is also a coping mechanism to withstand heat.
Misting to cool down is also a good idea. Make sure the water with which you are cooling them down is not ice cold..otherwise they might catch pneumonia.
I live in Florida and my cham basks in those temps and even hotter. You just have to make sure they are not forced to be exposed to the sun only. Shade is key and providing water as said and let it be their choice if they want to be in the sun or not. I have also had my chameleon outside on days where the ambient temp was above 90 for a good period of the day and he was fine as long as provided shade.