Gabon has a total of 2,551 km of international boundaries. It borders Equatorial Guinea
(350 km) and Cameroon (298 km) to
the north and the Republic of the Congo (1,903 km) to the
east and south. Gabon lies on the equator.
From June to September there is virtually no rain but high humidity; there is
occasional rain in December and January. During the remaining months, rainfall
is heavy. The excessive rainfall is caused by the condensation of moist air
resulting from the meeting, directly off the coast, of the cold Benguela Current from
the south and the warm Guinea Current from the north. At Libreville,
the average annual rainfall is more than 2,540 mm (100 in). Farther north on the
coast, it is 3,810 mm (150 in).