I live in a sub-tropical area of Queensland, where the humidity is always 60-75%, and on the really humid days can be as high as 95%. For someone that dislikes humidity, it's akin to hell. Stamps and humidity don't mix, and I've suffered some substantial losses, mainly of German and Canadian stamps, where they have adhered themselves to stockcards and stocksheets. The gum used by those two countries seems to be particularly susceptible to humidity and once stuck, they stay stuck. Humidity also creates mould, another sworn enemy of stamps. To minimise the losses, I use disposal dehumidifiers (up to four in a bedroom-sized area), but I'm gearing up for the next peak with a digital hygrometer to measure humidity in the room. They're very cheap and highly recommended. I don't plan on having any more losses.