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The entire Mananara Nord National Park consists of 23,000ha terrestrial park and 1,000ha marine park. The altitude reaches from 0m to 569m. The park is subject to a humid tropical climate. The average temperature is 25.2°C and the humidity is constantly high. It rains most of the year and can reach up to 2,900mm per year. There is a warm and rainy season from September to March and a cooler season from April to September. Mananara is often a passage area for tropical cyclones.
The Precambrian basement of Mananara, dating back 2,750 million years, belongs to the Antongilian system. Following geological metamorphisms that led to this substrate of rocks composed of amphibolites, micaschists, greenschist and schist, granitic intrusions of about 770 million years ago appeared which, together with Neocene alteration and erosion, are responsible for the orthogonal shape of the region's relief with narrowly linear valleys, rock walls, cascades and waterfalls, falling rocky shores and the hydrographic network following the lines of the landscape and valleys. This explains the difficulty of access to monitor the park, the history of linear fragmentation of the forest and the human occupation along the lines of valleys. The density of vegetation and the ability of forest regeneration worsen the problems as they favour the camouflage of offenders. Due to presence of the South Equatorial Current coming from South Asia that runs along the east coast to become Madagascar's southward current, this current brings warm surface waters in all seasons and conditions the water temperature to never drop below 18°-20°C. In order to develop, coral reefs require warm, clear water (above 18°C) on a shallow bottom with 30 to 35% salinity, which is the case for the Mananara Nord Marine Park. At the highest sea (during high tide minus the half maximum hight of a wave) the water is between 25m and 35m deep. The Malagasy east coast is swept throughout the year by the Alizé. The average wind speed is 20m/s.
