Gabon has the moist, hot climate typical of tropical regions. The hottest month is January, with an average high at Libreville of 31°C and an average low of 23°C. Average July temperatures in the capital range between 20º and 28°C.
The main river in Gabon, Ogooue River, arcs across the entire country, with major tributaries including Ivindo and Mpassa. Its mouth is at Port Gentil, on the Atlantic Coast, and it originates in the Republic of the Congo.