This paper analyzes the effects of weather anomalies on migration in sub-Saharan Africa. We present a theoretical model that demonstrates how weather anomalies induce rural–urban migration that subsequently triggers international migration. We distinguish two transmission channels, an amenity channel and an economic geography channel. Based on annual, cross-country panel data for sub-Saharan Africa, we present an empirical model that suggests that weather anomalies increased internal and international migration through both channels. We estimate that temperature and rainfall anomalies caused a total net displacement of 5 million people during the period 1960–2000, i.e. a minimum of 128,000 people every year. Based on medium UN population and IPCC climate change projections, we expect future weather anomalies to lead to an additional annual displacement of 11.8 million people by the end of the 21st century.