The Climate and Relief
Equatorial Guineais characterized by having a clearly equatorial climate habitual for areas near the Equator. This climate is very similar to the tropical climate, and both share limited temperature ranges and high temperatures. The major difference is that the rainy season of the tropical climate is more irregular and less intense, while in the equatorial climate the rains are very abundant and regular, and normally exceed 1,500 to 2,000 mm per year.
From that point, each of the regions of Equatorial Guinea has its own characteristics.
Island Region: Bioko and Annobon
In the island region we find an equatorial-type climate on Bioko, with a dry season from November to March and a rainy season from April to October. The climate is temperate, influenced by the warm ocean currents and by the relief of the island, with a monsoon component in the southern part and an average annual temperature of 25ºC, which can oscillate about 2ºC.
The climate of Annobon is similar, with a dry season from June to October and a wet season from November to May. The average annual temperature is usually around 26ºC.
The climate of the continental region presents two dry seasons: the first of them is between December and the middle of February, and the second and most important is from July to September. We can also find two rainy seasons: one in March and another in September to November.
In the continental region the average annual temperature is around 20ºC, with an oscillation that does not exceed 5ºC. The principal precipitations were produced during the months of September and December, from 1,800 to 3,800 mm, and the relative humidity is around 90%, descending to 85% in the dry season.
The wettest areas are in the mountainous area of Monte Mitra and, on the border with Gabon, the basin of the Mitemele.
By being structured in two areas, the island and continental areas, the geographic variety and relief of Guinea is as broad as it is rich.
The continental area
This is formed on the one hand by the coastal area that becomes more mountainous as we go inland, where we find a series of mountain chains called “the Seven Mountains”. One of the greatest riches of Equatorial Guinea is, precisely, the exuberant and lush forests that we find in this land of gentle hills.
The relief of the continental region can be summarized in three types of formations:
• The coastal area, of sand and marl.
• The inland area, mainly of gneiss.
• The eastern area, of granite.
Orography of the continental region:
1. Kie-Ntem Plateau:descends towards the west and continues to the coast through the flatlands of Ntem.
2. Central flatlands:descends towards the Muni and Mitemele basin and is furrowed by rocky outcropping.
3. Mongouba Platform:we find this in the eastern area of the Niefang mountain chain, with peaks that reach 1,200 m in altitude.
4. Mitra Massif:we find the highest areas in the continental region, Mount Mitra or Mount Alen, in the southern of the Niefang Chain.
5. The Muni and Mitemele basin:is a trough between the Niefang Chain on one side and the Montes de Cristal on the other.
6. Flatlands to the west of the Niefang Chain.
The island area
The Bioko is of volcanic origin, and therefore, mountainous and also with forests. From any part of its area we can see the silhouette of the Basile peak, formerly known as the Santa Isabel peak. As for Annobon, its orography is of volcanic origin, comprised mainly by basaltic rocks.
Orography of the Insular Region:
1. Bioko. The island is divided into a north block and another south block, separated by a central depression near Musola and it forms part of the volcanic chain that diagonally crosses from the Lake of Chad to the Island of Ascension.
Its orography is of volcanic origin, with a landscape of deep valleys and steep slopes. The island is comprised completely of volcanic origin. We find three calderas: Basile Peak (3,011 m) in the north area and Biao Peak (2,009 m) and the Gran Caldera of Luba (2,261 m) in the southern area.
2. Annobon. The island is found in the volcanic range, mentioned above, along with Bioko, Sao Tome and Principe.
1. Caldera of the A Pot lake.
2. Crater of the southern area to the east of Punta Manjob.
3. Corridor that joins the Bays of San Pedro and Santa Cruz, running through the Anganchi river.