Fog and stratus clouds (FSt) provide an important input of water to the biota of the coastal parts of the hyper-arid Namib [1,2]. Its climatology is relatively well understood but only recently observational evidence showed the role the marine stratus clouds which - dominantly advected from north-west - produce with its seasonal height variation and the interplay with the ascending terrain the distinct fog climatology of the central Namib [3,4]. This advection-dominated fog regime was questioned recently based on isotope analyses and led to the suggestion that it might be rather a radiation-dominated fog regime in the coastal Namib.