Weak, moderate, strong, ‘super’: what the El Niño strength labels mean

Headlines call El Niño "strong", "very strong" or even "super". Here is what the official labels mean.

The ladder. IMD explains that operational centres grade El Niño by the Oceanic Niño Index (ONI) or the newer Relative Oceanic Niño Index (RONI), a three-month average of how far the Niño-3.4 region of the Pacific is above normal:

• Weak: 0.5 to under 1.0°C
• Moderate: 1.0 to under 1.5°C
• Strong: 1.5 to under 2.0°C
• Very strong: 2.0°C or more

La Niña uses the same steps below zero.

Where this year sits. NOAA's October 2026 strength outlook gives a 100% chance that the index reaches "very strong" levels (2.0°C or more) in October–December 2026, and 81% for December–February. These are forecasts, not observations.

What about "super"? IMD says there is "at present no universally accepted scientific definition of a 'super' El Niño." It is a media term, not an official class.

Strength is not the same as impact. The World Meteorological Organization says the strength of an El Niño "does not translate directly into the magnitude of impacts in any region." IMD adds that impacts also depend on the event's pattern, timing and length, and on other drivers such as the Indian Ocean Dipole. Two events of similar strength can affect India very differently.

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