The Indian Ocean Dipole (IOD) is an air-sea coupled climate mode in the Indian Ocean with some positive and negative events. It has large climate impacts: floods in East Africa and droughts in Indonesia and parts of Australia and Indian summer monsoon rainfall remains above normal during a positive IOD. IOD generally starts to develop in boreal summer, peaks in fall and terminates in winter, subject to the strong seasonal surface winds.

Three consecutive positive IOD events have occurred in 2006, 2007 and 2008. No such previous occurrence had already been recorded.