The largest cholera epidemic of modern times began during the autumn of 2016 in Yemen, under ongoing war conditions. What exactly caused the epidemic to emerge is unclear. It is suggested that a combination of the impact of the strong El Niño of 2015-16 on cholera incidence in Somalia, followed by southwestern winds over the Gulf of Aden throughout the summer of 2016, contributed to the disease spreading through dissemination of cholera-contaminated flying insects (chironomids) from the Horn of Africa to Yemen.