In the Book Mig FAQ, which despite my concerns over the price has turned out to be a superb and complete explanation albeit in mainly pictorial format of the techniques that he has added to the modellers [auto-censored]nal over the past few years and in respect of rust in the desert he puts forward an interesting fact regarding the formation of rust. Although moisture is normally considered in the formation of rust, it is in fact caused by oxidation, which therefore means that as this is the action of the oxygen in the air that we breath it means that this will see rust form in whatever environment we take machinery too. I suppose that as damp climates produce faster rusting that you would not see the same extent in a such a short timescale. However in the first Gulf War, were there not reports of rain, snow, hail and mud in some of the written reports, so it is probably up to the individual as to how much rust is seen on your project.
I hope this does not cause any discontent and as I am not a scientist I do not know the actual working of metals rusting.
Regards,
John