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week of Nov 4 · checked Nov 12
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Pacific Ocean temperature today

Data: NOAA CPC · week of Nov 4

Weekly anomaly by region

°C · recent weeks

ONI over recent years

°C, 3-month running mean
Above +0.5 °C is El Niño; below −0.5 °C is La Niña. Strength: weak, moderate (from 1.0), strong (1.5) and very strong (2.0).

Which index is which?

IndexValueWhat it measures
Niño 3.4+3.3 °CHow far above normal the central Pacific was in the week of Nov 4. It reacts fast and swings a lot.
ONI+2.46 °CThe 3-month average (Aug–Oct 2026) of Niño 3.4. It is the index used to compare events back to 1950.
RONI+1.97 °CThe "relative" ONI (Aug–Oct 2026): it removes the overall warming of the tropical oceans. It is now NOAA's main index.
That is why you see different numbers on different sites: they are different indices, and they are all correct.