I'm just going to throw in my two cents here, I read your original post JP, but not the entire thread yet, so forgive me if this has been addressed: Why is the region's climate referred to as Mediterranean? It's a reference that we understand, of course, but it's a climate archetype labeled by a region that doesn't exist in our characters' world and therefore describes nothing about the region to our characters: it's meaningless to them.
It's an easy fix as well: semi-arid, sub-tropical. This description also makes sense if we are to compare Dwilight to Australia. In fact, there are a few things Dwilight has in common with Australia: the same hemisphere, a desert in the center of the continent, and semi-arid and sub-tropical coastlines.