Over the last few months, heavy rains have flooded every one of Chad's 23 provinces, burst a dam in northern Nigeria, damaged ancient buildings in Niger's desert town of Agadez, and killed more than 1,460 people in the countries on the fringes of the Sahara, according to U.N. aid agency OCHA.

Residents of Chad, Mali, and Niger waded through flood waters or used boats along submerged streets in recent weeks. They are among 6.6 million people affected by West and Central Africa’s monsoon. Over 8.