Why does the Congo basin contain the world’s second largest rainforest?

The Congo basin supports the world’s second-largest rainforest primarily due to the equatorial climate that prevails over a significant portion of the region.1

This climate is characterized by high temperatures and consistent, heavy precipitation throughout the year, which are essential for sustaining dense evergreen forest. The region's climate is heavily influenced by the intertropical convergence zone (ITCZ), where trade winds meet to force unstable tropical air upward, resulting in prolonged rainfall. Because the basin is situated astride the Equator, these conditions allow the forest to spread across the central depression, creating a vast, continuous ecosystem.21