i have not kept chams outside but i think the typical temp requiremnts would be benificial.
say around 100 on the high end and 55 on the low end.
you will want to make sure the cham has lots of hiding placing from the sun rain and wind. and an automatic mister will be required on hott summer days. cool nights are fine i would want to be sure that you are in an area where you know you are not gong to get a freak cold night. ( below 50 )
being outside one thing you will need to highly consider is predators, typical screen cages will offer little in the way of protaction from large birds, racoons and other animals.
also if your cham is spending most of its time outside you will not want to use the calcium plus everyday as it is meant for a animal kept indoors. instead you would want a plain calcium and a mutivitamin. using the calcium at most feedings and the mutivitamin a few times a month.
hope that helps a bit.