Guarding against degradation processes is a key objective for the application of self-healing and active coating protection. However, the study of atmospheric interactions with surfaces is difficult due to the stochastic nature of weather “events”. These stochastic events include, rain events, condensation and evaporation cycles, temperature lagging or leading in occluded volumes, surface condition, aerosol generation and large scale climatic changes such as el-nino/la nina events or global warming. This chapter examines in detail, many of these influences and looks at the role that they play in the deposition of corrodents onto surfaces. It also examines condensation cycles where these corrodents become wet and corrosive.