Weekly update · March 18, 2026
El Niño Update, Week of March 18, 2026: Niño 3.4 at 0.0 °C
In the week of March 18, 2026, the sea surface temperature anomaly in the Niño 3.4 region — NOAA's main El Niño indicator — was 0.0 °C (27.3 °C actual), which corresponds to neutral conditions.
Compared with the previous week it rose 0.1 °C, and over the last four weeks it rose 0.1 °C.
Off the coast of Peru and Ecuador (Niño 1+2) the anomaly was +1.4 °C (it held steady); this coastal warming is what most affects rain on the South American Pacific coast.
One year earlier, Niño 3.4 was at -0.1 °C.
| Region | Area | Anomaly | vs. last week |
|---|---|---|---|
| Niño 1+2 | coast of Peru and Ecuador | +1.4 °C | 0.00 |
| Niño 3 | eastern Pacific | +0.3 °C | -0.10 |
| Niño 3.4 | central Pacific (official index) | 0.0 °C | +0.10 |
| Niño 4 | western-central Pacific | +0.3 °C | +0.20 |
Niño 3.4, previous 52 weeks
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Frequently asked questions
Was there an El Niño in the week of March 18, 2026?
The weekly Niño 3.4 anomaly was 0.0 °C, within the neutral range (−0.5 to +0.5 °C). NOAA declares an event using the 3-month ONI and the atmospheric response.
Where do these numbers come from?
From NOAA's Climate Prediction Center weekly OISST v2.1 sea surface temperature data, published every Monday.
Source: NOAA CPC weekly OISST v2.1 (public domain). Generated automatically by El Niño Forecast; free to cite with a link.