Hundreds of thousands of people in East Africa are affected by heavy rains and floods linked to record-breaking temperature changes in the Indian Ocean.

A flooded fuel station in Mombasa following ongoing heavy rains.

The western Indian Ocean has been about two degrees warmer this month than the eastern Indian Ocean. As a result, higher evaporation off the African coastline is being dumped inland as rainfall: a simplified description of 2019's positive Indian Ocean Dipole (IOD) episode.

This year, the IOD is "enormous", according to climate scientist Saji Hameed, who studies the phenomenon at the University of Aizu, Japan.

Hameed told The New Humanitarian that equatorial East Africa is "very, very likely" to be unusually wet from October to December, adding: "November is the most dangerous month as far as IOD impacts are concerned, as enhanced rains reach far into highlands and the watersheds of several rivers."

In an email response to questions, the Kenya-based regional Intergovernmental Authority on Development Climate Prediction and Applications Centre (ICPAC) confirmed the pattern.