Aim: To explore the magnitude and spatial patterns of last glacial stage orbitally forced climatic changes and suborbital climatic fluctuations in southern Africa, and to evaluate their potential roles in determining present biodiversity patterns. Main conclusions: Suborbital climatic fluctuations during the last glacial stage were probably of considerable magnitude in southern Africa. This may account for apparent inconsistencies between regional palaeoclimate records, as well as being key to determining present biodiversity patterns. Keywords: Birds, Cape Floristic Province, endemics, Fynbos, Heinrich events, hosing experiments, last glacial stage, South Atlantic, species distribution models, Succulent Karoo.