There is usually more rainfall in the mountains than in the neighbouring plains. The rainy season often starts earlier and might last longer. The remoteness, which was an advantage in the past, is today a disadvantage and from an ethnographic point of view of historical interest only. The lack of infrastructure has led to downhill migration, causing conflicts over land in adjacent plains.
The inaccessibility of the mountains has been given as the main historical reason why the Northern Mandaras have become so densely populated over time. This argument is closely related to the history of slave raids and neglects the climatic conditions as another possible explanation.
The annual rainfall is considerably higher in the mountains than in the plains of the same latitude. On the plateau of Mokolo we have 958mm, but in the plain of Maroua we have only 786mm (Hallaire 1991:17). Considering the short period of rainfall in the Sundano-Sahelian zone, this must be seen as an advantage.