El Nino & La Nina

ENSO indices, upper-ocean temperature, and their relationship to global surface temperature.

Figures on this page

1. Recent ENSO and global temperature
2. Extended ENSO indices (1950–present)
3. ENSO and global temperature relationships
4. ENSO cycle comparisons: Nino3.4 SST, RONI, and upper 300 m
5. Pacific Decadal Oscillation (PDO)
References
External ENSO resources

Recent ENSO and Global Temperature

Weekly unadjusted Nino 3.4 SST anomaly, NOAA OISSTv2.1, 28 May 2025 – 3 Jun 2026.

Weekly Nino 3.4 Sea Surface Temperature (unadjusted). Anomalies relative to 1991-2020 base period, in the region 5ºN-5ºS, 170-120ºW.

Data: 28 May 2025 - 3 Jun 2026. Data source: ref. [1a].

Nino 3.4 sea surface temperature anomalies, Jan 1979–May 2026.

Nino 3.4 sea surface temperature (Jan 1979 – May 2026). Monthly mean SST anomalies relative to the 1991–2020 base period, in the region 5ºN-5ºS, 170-120ºW.
PDF. Data through May 2026. Data source: ref. [1b].

Relative Oceanic Nino Index (RONI) anomalies, DJF 1979–MAM 2026.

Relative Oceanic Nino Index (RONI, DJF 1979 – MAM 2026). 3-month running mean SST anomalies relative to the 1991–2020 base period, in the region 5ºN-5ºS, 170-120ºW.
PDF. Data through MAM 2026. Data source: ref. [3].

Equatorial Pacific upper 300 m temperature anomalies, Jan 1979–May 2026.

Equatorial Pacific upper 300 m temperature (180–100°W, Jan 1979 – May 2026). 3-month running mean temperature anomalies relative to the 1981–2010 base period.
PDF. Data through May 2026. Data source: ref. [2].

Lead–lag correlations between global surface temperature and Nino 3.4 / upper 300 m temperature.

Correlation of global surface temperature with Nino 3.4 and upper 300 m temperature. Lead–lag correlations based on detrended 12-month running means for 1979–2025.
PDF. Data through May 2026. Peak correlations occur at about 4 months for Nino3.4 and about 9 months for upper 300 m temperature. Underlying data sources: ref. [4], ref. [1b], ref. [2].

Extended ENSO Indices (1950–Present)

Nino 3.4 sea surface temperature anomalies, Jan 1950–May 2026.

Nino 3.4 sea surface temperature (Jan 1950 – May 2026). Monthly mean SST anomalies relative to the 1991–2020 base period, in the region 5ºN-5ºS, 170-120ºW.
PDF. Data through May 2026. Data source: ref. [1b].

Relative Oceanic Nino Index (RONI) seasonal anomalies, DJF 1950–MAM 2026.

Relative Oceanic Nino Index (RONI, DJF 1950 – MAM 2026). 3-month running mean SST anomalies relative to the 1991–2020 base period, in the region 5ºN-5ºS, 170-120ºW.
PDF. Data through MAM 2026. Data source: ref. [3].

ENSO and Global Temperature Relationships

Comparison of global surface temperature with Nino3.4 and equatorial Pacific upper-300 m temperature, based on detrended 12-month running means for selected detrending periods.

Comparison of global surface temperature with Nino3.4 and equatorial Pacific upper-300 m temperature, detrended for 1979–2025.

Global surface temperature, Nino3.4, and equatorial Pacific upper 300 m temperature (detrended for 1979–2025). Detrended 12-month running means, with Nino3.4 and upper-300 m temperature scaled by 0.1.
PDF. Data through May 2026. Underlying data sources: ref. [4], ref. [1b], ref. [2].

Comparison of global surface temperature with Nino3.4 and equatorial Pacific upper-300 m temperature, detrended for 1979–2005.

Global surface temperature, Nino3.4, and equatorial Pacific upper 300 m temperature (detrended for 1979–2005). Detrended 12-month running means, with Nino3.4 and upper-300 m temperature scaled by 0.1.
PDF. Data through May 2026. Underlying data sources: ref. [4], ref. [1b], ref. [2].

Comparison of global surface temperature with Nino3.4 and equatorial Pacific upper-300 m temperature, detrended for 1979–2015.

Global surface temperature, Nino3.4, and equatorial Pacific upper 300 m temperature (detrended for 1979–2015). Detrended 12-month running means, with Nino3.4 and upper-300 m temperature scaled by 0.1.
PDF. Data through May 2026. Underlying data sources: ref. [4], ref. [1b], ref. [2].

Additional versions for other detrending periods are available on the More Figures page.

ENSO Cycle Comparisons

Comparison of the present ENSO cycle with selected past El Nino periods using Nino3.4 SST, Nino3.4 RONI, and equatorial Pacific upper-300 m temperature anomalies. Curves are based primarily on three-month running means, with the latest point extended using the most recent available monthly data.

For the 2025–present curves, the Nino3.4 SST and upper-300 m plots show the three-month running mean extended through May 2026 using the May monthly value. The RONI plots extrapolate the May point using the average change in RONI three-month averages since February 2026.

Nino3.4 SST anomalies for selected super El Nino periods, base period 1991–2020.

Nino3.4 SST, selected super El Nino periods (base 1991–2020). Three-month running mean SST anomalies shown for 1981–1984, 1996–1999, 2014–2017, and 2025–present.
PDF. Data through May 2026, with the 2025–present curve extended as described above. Data source: ref. [1b].

Nino3.4 SST anomalies for selected weaker El Nino periods, base period 1991–2020.

Nino3.4 SST, selected weaker El Nino periods (base 1991–2020). Three-month running mean SST anomalies shown for 2008–2011, 2017–2020, 2022–2025, and 2025–present.
PDF. Data through May 2026, with the 2025–present curve extended as described above. Data source: ref. [1b].

Nino3.4 RONI for selected super El Nino periods, base period 1991–2020.

Nino3.4 RONI, selected super El Nino periods (base 1991–2020). Three-month running mean anomalies shown for 1981–1984, 1996–1999, 2014–2017, and 2025–present.
PDF. Data through May 2026, with the 2025–present curve extended as described above. Data source: ref. [3].

Nino3.4 RONI for selected weaker El Nino periods, base period 1991–2020.

Nino3.4 RONI, selected weaker El Nino periods (base 1991–2020). Three-month running mean anomalies shown for 2008–2011, 2017–2020, 2022–2025, and 2025–present.
PDF. Data through May 2026, with the 2025–present curve extended as described above. Data source: ref. [3].

Equatorial Pacific upper 300 m temperature anomalies for selected super El Nino periods, base period 1991–2020.

Equatorial Pacific upper 300 m temperature, selected super El Nino periods (base 1991–2020). Three-month running mean temperature anomalies for the 180°W–100°W region, shown for 1981–1984, 1996–1999, 2014–2017, and 2025–present.
PDF. Data through May 2026, with the 2025–present curve extended as described above. Data source: ref. [2].

Equatorial Pacific upper 300 m temperature anomalies for selected weaker El Nino periods, base period 1991–2020.

Equatorial Pacific upper 300 m temperature, selected weaker El Nino periods (base 1991–2020). Three-month running mean temperature anomalies for the 180°W–100°W region, shown for 2008–2011, 2017–2020, 2022–2025, and 2025–present.
PDF. Data through May 2026, with the 2025–present curve extended as described above. Data source: ref. [2].

Pacific Decadal Oscillation (PDO)

Note: Running-mean curves necessarily end earlier than the final monthly datum.

PDO index, 1880–2026, with seasonal means and 12-month running mean.

PDO index (1880–2026). Monthly PDO index with seasonal means and 12-month running mean.
PDF. Data through May 2026. Data source: ref. [5].

PDO index, 1950–2026, with seasonal means and 12-month running mean.

PDO index (1950–2026). Monthly PDO index with seasonal means and 12-month running mean.
PDF. Data through May 2026. Data source: ref. [5].

References

  1. NOAA Climate Prediction Center (CPC) indices .
    (a) Data table (Nino 3.4; Unadjusted weekly OISSTv2.1; 1991–2020 base): wksst9120.for .
    (b) Data table (Nino 3.4; Monthly ERSSTv5; 1991–2020 base): ersst5.nino.mth.91-20.ascii .
  2. NOAA PSL Central Pacific heat content (upper 300 m temperature anomaly) . Data table (CPC equatorial upper-300 m temperature anomaly index; 180°W–100°W): heat_content_index.txt .
  3. NOAA CPC Relative Oceanic Nino Index (RONI) . Data table: RONI.ascii.txt .
  4. NASA GISS Surface Temperature Analysis (GISTEMP v4) .
  5. NOAA NCEI Pacific Decadal Oscillation (PDO) Index . PDO plots updated through May 2026 use NOAA ERSSTv6 sea surface temperature data. ERSSTv6 description: NOAA PSL ERSSTv6 .

See also NOAA weekly ENSO 30+ presentation pages and records of some figures.

Additional legacy ENSO figures are available on the Global Temperature – More Figures page under the section "El Nino & La Nina – Archive Figures".