We are now in
El Niño
According to NOAA CPC ↗
Updated on 10 September 2026
El Niño Advisory
Relative Niño 3.4 Year comparison
1982199720152026 · latest
Sea surface temperature anomalies and ENSO indices
Conventional sea surface temperature anomalies quantify departures from the 1991–2020 climatological baseline. Relative anomalies additionally account for contemporaneous temperature anomalies across the broader tropics. NOAA publishes both weekly datasets. The Relative Oceanic Niño Index (RONI) is a separate three-month index for the Niño 3.4 region.
Index definitions and methodology →Data sources and archival records
Relative weekly regions
Relative OISST v2.1 · 1991–2020 baseline.
9 September 1981 – 2 September 2026.
2,348 observations.
Conventional weekly regions
OISST v2.1 · 1991–2020 baseline.
2 September 1981 – 2 September 2026.
2,349 observations.
Seasonal RONI
Relative ERSST v6 · 1991–2020 baseline.
DJF 1950 – JJA 2026.
919 observations.