Weathering is a process that reduces concentrations of radio nuclides in the environment by several agents such as rain, wind and plant growth and it affects both long-term ground shine doses and long-term resuspension doses. Though parameters related to weathering are provided in the MACCS code for radiation-exposure calculations, appropriate input values can vary among countries and environmental conditions. In this study, we review literature data on weathering processes, with a focus on those obtained in Japan after the FDNPP accident and discuss the sensitivities of long-term doses against these weathering parameters.