Live in Florida with basically 100% humidity. So yah…. Not sure I can convince the wife we need to AC the garage to keep my rotors from rusting but I guess I’ll start preparing the case….Don't thank me until it's proven true! All iron alloy rotors will oxidize a little, but it depends on a number of factors as to whether it's visible enough to be cosmetically undesirable. If you're parking indoors you're way ahead of the game. Controlling humidity in that space is a big part of the outcome... if it's not climate controlled, consider adding a dehumidifier to cut the water in the air on rainy days.