Hmm, I haven't really lived in a desert climate. You might want to ask on the NaturallyCurly forums for those familiar with it.
Your shampoo and conditioner are free of those harsher sulfates, so that's probably fine. Is there a particular reason for why you wash your hair every other day? Most curlies can go several days in between washing. While you're using a gentle shampoo, washing it that often might be causing issues, though you do note that you're using a mask. It could be a matter of your hair needs more moisture. Cutting back on how much you shampoo, maybe just focusing on your roots for shampooing and trying out some leave-in conditioner.
Everyone's hair and curls can be so different, so it can be a matter of trial and error to see what works best for you. Some do the no-(sham)poo method, some low-poo, and others a variety. You may discover that you can actually have a crazy amount of product in your hair and it will still look and feel incredibly natural.