SummaryContinuous recordings of VLF electromagnetic radiation were statistically compared with physical conditions of the atmosphere. The VLF level is closely associated with the distance to thunderstorms and therefore related to the dynamical weather processes. In agreement with previous studies, we found that the movement of the VLF sources is associated with the frontal system and especially with the passage of cold fronts. The VLF level is increased mainly by cold fronts of the anatype. The rainfall intensity is closely correlated to the electric discharge formation and thereby also to the VLF activity in the anafronts, while the katafronts often give rise to slight precipitation and few flashes of lightning. The atmospheric pressure changes accompanying the anafronts are largely correlated with the VLF level and the precipitation intensity. The mean diurnal and annual variations of the VLF level are determined by the occurrence of lightning activity. During the summer the daily trend is pronounced due to the insolation effect. The present study shows that the VLF level is determined to a high degree by fairly well defined areas with lightning discharges, which can be localized with automatic lightning location systems or forecasted by the weather services.