Aha - betcha have a swamp cooler, that will get you every time. We also have our rainy seasons here in the desert, they just don't last as long as, say, Washington's, for example.
Anywhere people live, you will have humidity of one sort or another, or our skins will dry and crack, so yes, you do have a humid environment, low, but it's there. Get a thin tool to clean in there with a cloth and Hoppes #9 or Weapon Shield, then make sure you keep a dab of WS or whatever your favorite rust blocker is right there.
