I live in what is basically a desert climate. It is bone dry for much of the year, and even when it rains it dries up pretty quick and doesn’t last long. I have visited the west coast fairly frequently, and the moist air there makes a person’s skin and hair totally different. I like the dry climate, but my skin and hair love the moister air of the coast. In these dry conditions moisturizer is essential, and not just a nice thing to have with out a great body moisturizer in the morning, and a generous application of face moisturizer morning and evening (sometimes in between) my skin would dry up and blow away, and that could be inconvenient. Seriously, I go through tubs of the stuff, and the face cream isn’t cheap. I don’t like the mugginess of the coast but sometimes I think that the moist air would make it worth it. On the other hand, it can be something like 90 degrees here and you don’t feel it much.
With all that moisturizing you have to pick your products pretty carefully. You don’t want to be applying gobs of a product that is going to do long term damage to your skin.