https://www.flickr.com/photos/eyabu/shares/08rLEA
Hi from Arizona!
New member, I have a small collection of orchids in several of my windowsills - most of them Phels since I am addicted to the sale rack in Lowe's

but a couple of Paphs , Catts and two Oncidiums. I am definitely partial to Oncidiums and so far they seem to bear well the Arizona dryness, but it is a struggle... at least we have light aplenty!
I would love to hear from other people that live in very dry climates and what they do to help their plants thrive. I have experimented with a few watering schedules and potting media but I don't think I have hit the right ones yet.

Hopefully this shows... it is a self made humidity tray at one of my windows.