I absolutely think it varies from person to person. I don't think either dry or humid affects me all that much, as I get a good dose of both living in the northeast. I do notice that it's much harder for me to cough up stuff in the winter because everything in there almost seems dry and stuck. But the thicker air does make it feel like it's harder to breathe, but I think that goes for anyone. The colder air in the winter is also a little rough on me though.