Sao Tome and Principe Factsheet - Geography & Climate

Geography & Climate

Location and islands

• Equatorial archipelago in the Gulf of Guinea, Central Africa, straddling the Equator. 
• Situated approximately 300–350 km west of the coast of Gabon and 225–250 km off the African mainland. 
• Composed of two main volcanic islands: – São Tomé: 859 km² (largest island, ~95% of population) – Príncipe: 142 km² (autonomous region) 
• Distance between São Tomé and Príncipe: ~150 km. 
• Plus several smaller rocky islets (Rôlas, Cabras, Tinhosas, Bombom, etc.).

Land area, coastline, topography

• Total land area: 1,001 km² (some sources 964 km²).
• Coastline: 209 km.
• Volcanic origin, part of the Cameroon volcanic mountain line.
• Steep, dramatic topography with dense rainforest interior: – 
• Highest point: Pico de São Tomé – 2,024 m 
• Highest point on Príncipe: Pico do Príncipe – 948 m 
• Iconic landmark: Pico Cão Grande (dramatic volcanic needle).

Exclusive Economic Zone (EEZ)

• Approximately 160,000 km² — ~160 times the land area. 
• Includes the national EEZ and the Joint Development Zone (JDZ) shared with Nigeria (40% São Tomé and Príncipe / 60% Nigeria). 
• Exploration blocks awarded to major oil companies (Shell, Galp, TotalEnergies, BP), but no commercial oil production yet.

Climate and seasons

•  Tropical equatorial climate: hot and humid year-round (26–32 °C). 
• Two distinct seasons: – Rainy season: September/October to May (heaviest rainfall Oct–May; annual precipitation 800–7,000 mm depending on altitude). 
• Dry season ("Gravana"): June to August/September – milder temperatures, lower humidity, occasional mist. 
• Entire national territory designated UNESCO Biosphere Reserve in 2025 — the first country in the world to have 100% of its land and sea area under this status.