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El Niño Advisory in effect — Niño 3.4 at +2.6 °C Latest updates

El Niño Monitor

The El Niño timeline

Four centuries of El Niño — from the fishermen of Paita to satellite-era super events. Event strengths follow NOAA’s Oceanic Niño Index (ONI): weak (+0.5–0.9 °C), moderate (+1.0–1.4 °C), strong (+1.5–1.9 °C) and very strong (≥ +2.0 °C).

Key milestones

  1. 1600s

    Peruvian fishermen name the warm current 'El Niño'

    Fishermen of Paita, northern Peru, notice a warm current arriving around Christmas and name it after the Christ Child — 'El Niño de Navidad'.

    Source: NOAA — Understanding El Niño (opens on the source’s website in a new tab)

  2. 1877–78

    The Great Drought and Great Famines

    One of the strongest El Niños ever reconstructed drives simultaneous drought across India, China, Brazil and beyond; famines kill tens of millions.

    Source: Singh et al. 2018, Journal of Climate (AMS) (opens on the source’s website in a new tab)

  3. 1891–92

    First written scientific records

    Luis Carranza describes the coastal countercurrent in the Lima Geographical Society Bulletin; Captain Camilo Carrillo records the name 'El Niño' in scientific literature.

    Source: University of Washington — El Niño FAQ (opens on the source’s website in a new tab)

  4. 1920s

    Gilbert Walker identifies the Southern Oscillation

    Working to predict the Indian monsoon, Walker discovers the pressure see-saw between Tahiti and Darwin — the atmospheric half of ENSO.

    Source: NOAA Climate.gov ENSO Blog (opens on the source’s website in a new tab)

  5. 1969

    Bjerknes couples ocean and atmosphere

    Jacob Bjerknes shows El Niño and the Southern Oscillation are one coupled phenomenon, describes the feedback that now bears his name, and names the Walker Circulation.

    Source: NOAA AOML — Overview of ENSO understanding (opens on the source’s website in a new tab)

  6. 1985–94

    The TOGA program builds the Pacific observing system

    After 1982–83 caught science off guard, the international TOGA program deploys the ~70-buoy TAO array across the equatorial Pacific, completed in 1994.

    Source: NOAA PMEL — TOGA-TAO (opens on the source’s website in a new tab)

  7. 1986

    First successful El Niño forecast

    Mark Cane and Stephen Zebiak publish the first coupled-model El Niño forecast in Nature, correctly predicting the 1986–87 event.

    Source: Cane, Zebiak & Dolan 1986, Nature (opens on the source’s website in a new tab)

  8. 1992

    TOPEX/Poseidon watches the ocean from space

    The NASA/CNES altimeter begins measuring sea-surface height to ~4 cm, letting scientists watch Kelvin waves and El Niño heat move across the Pacific.

    Source: NASA JPL — Sea level (opens on the source’s website in a new tab)

  9. 2024

    Fourth global coral bleaching event declared

    NOAA declares the most widespread global coral bleaching event on record as the 2023–24 El Niño peaks amid record ocean heat.

    Source: NOAA Coral Reef Watch (opens on the source’s website in a new tab)

  10. 2026

    A potentially record-breaking El Niño develops

    El Niño returns and strengthens rapidly; models project a very strong peak in late 2026 — with agencies worldwide issuing advisories.

    Source: NOAA CPC — ENSO Diagnostic Discussion (opens on the source’s website in a new tab)

Every El Niño since 1950

Peak values from NOAA Climate Prediction Center ONI records (ERSSTv5). Borderline classifications can shift by ±0.1 °C between dataset revisions. Source: NOAA CPC — Oceanic Niño Index (opens on the source’s website in a new tab).

1951–52

+1.2 °C

Moderate

1952–53

+0.7 °C

Weak

1953–54

+0.8 °C

Weak

1957–58

+1.8 °C

Strong

Observed during the International Geophysical Year — data later used by Bjerknes

1958–59

+0.6 °C

Weak

1963–64

+1.4 °C

Moderate

1965–66

+2.0 °C

Very strong

Just over the very-strong threshold

1968–69

+1.1 °C

Moderate

1969–70

+0.9 °C

Weak

1972–73

+2.1 °C

Very strong

Peruvian anchoveta fishery collapse

1976–77

+0.9 °C

Weak

1977–78

+0.8 °C

Weak

1979–80

+0.6 °C

Weak

1982–83

+2.2 °C

Very strong

First 'super' El Niño of the satellite era; ~$8B damages

1986–87

+1.2 °C

Moderate

First successfully forecast event (Cane & Zebiak, 1986)

1987–88

+1.7 °C

Strong

1991–92

+1.7 °C

Strong

1994–95

+1.1 °C

Moderate

1997–98

+2.4 °C

Very strong

'El Niño of the century' — ~23,000 deaths, $30B+ damages

2002–03

+1.3 °C

Moderate

2004–05

+0.7 °C

Weak

2006–07

+0.9 °C

Weak

2009–10

+1.6 °C

Strong

2014–15

+0.8 °C

Weak

2015–16

+2.8 °C

Very strong

Highest ONI on record; global coral bleaching

2018–19

+1.0 °C

Moderate

2019–20

+0.7 °C

Weak

2023–24

+2.1 °C

Very strong

2023–24 global heat records. WMO: among the five strongest on record

2026–27

In progress

Ongoing. CPC's weekly Niño 3.4 index stood at +2.6 °C in the week centred on 19 August 2026. El Niño is strengthening, with a greater than 90% chance of a very strong event during the Northern Hemisphere fall and winter 2026-27. No final ONI yet — the seasonal index is only known once the event has peaked.