Food aid is now arriving in Niger, where some 2.5m people are going hungry. But charities are also concerned about neighbouring Mali, where some 1m people need food aid.
In both countries, some of those worst hit are nomads from the Tuareg community.
Here, Fatima Tou, 80, explains how her family has been affected by the lack of food.
I live in Tindjambane near Timbuktu, where I look after my seven grandchildren.