There are many factors that can influence when and how fast mold grows on your stored or water damaged documents. If you live in a humid climate, moisture levels and seasonal weather will have a large impact on the rate of mold growth. Cooler climates, however, are not much better off. In general, documents that have come into contact with water recently – through a flood, hurricane or water leak, for example – can begin to grow mold within just 48 hours.