The IOD question: is the Indian Ocean neutral or positive, and why agencies disagree

The Indian Ocean Dipole (IOD) is the Indian Ocean's own see-saw: the difference in sea temperature between a western box off Africa and an eastern box off Indonesia. It matters because, as IMD explains, a positive IOD can partly offset El Niño's drying effect on India. In 1997, a strong El Niño year, India's monsoon stayed normal.

Right now, the agencies do not agree.

IMD (1 October 2026): neutral IOD conditions are prevailing, and its Monsoon Mission model expects neutral conditions to continue through the northeast monsoon season.

Australian Bureau of Meteorology (13 October 2026): its IOD index is +0.88°C and has been above the +0.4°C positive threshold for five weeks; a positive IOD is "likely to develop".

WMO (8 October 2026): expects a positive IOD to peak in October, at about +0.5°C for October–December.

Why the difference? The statements were issued on different dates (1, 8 and 13 October), and each agency uses its own indices, data and models.

What we will do. We will not state the IOD phase firmly on Soshyal until the agencies line up. The IOD usually peaks between September and November and weakens quickly after, so its influence on this season will soon be clearer.

Join the El Niño help room on soshyal.com to ask questions and share what you see in your area.