Geography
Location: Western Africa; islands straddling the equator in the Gulf of Guinea west of Gabon.
Area: 1,001 sq. km. (386 sq. mi.); about the size of metropolitan Indianapolis, or one-third the size of Rhode Island.
Cities: Capital--São Tomé. Other cities--Trinidade, Santana, Angolares, Neves, Santo Antonio.
Terrain: Two small, volcanic islands.
Climate: Tropical, with wet and dry seasons, influenced by the mountainous topography.

Geography of Sao Tome
The islands of Sao Tome and Principe, situated in the equatorial Atlantic about 300 and 250 kilometers (200 mi. and 150 mi.), respectively, off the northwest coast of Gabon, constitute Africa's smallest country. Both are part of an extinct volcanic mountain range, which also includes the island of Bioko in Equatorial Guinea to the north and Mount Cameroon on the African west coast. Sao Tome is 50 kilometers (31 mi.) long and 32 kilometers (20 mi.) wide and the more mountainous of the two islands. Its peaks reach 2,024 meters (6,640 ft.). Principe is about 30 kilometers (19 mi.) long and 6 kilometers (4 mi.) wide. Swift streams radiating down the mountains through lush forest and cropland to the sea cross both islands.

At sea level, the climate is tropical--hot and humid with average yearly temperatures of about 27oC (80oF) and little daily variation. At the interior's higher altitudes, the average yearly temperature is 20oC (68oF), and nights are generally cool. Annual rainfall varies from 500 centimeters (200 in.) on the southwestern slopes to 100 centimeters (40 in.) in the northern lowlands. The rainy season runs from October to May.
source: http://www.state.gov