La Niña Index Dashboard

ENSO is an phenomena which extends over large spatial area and can have a different seasonal evolution from event to event. The different patterns have implications for climate impacts both locally and at a distance. The following indices all help characterize ENSO but at different locations and time scales. See the PSL news story on flavors of ENSO. Also see the web page to analyze and compare time series. There are two products available. First are plots of the progression of the latest data compared to historic La Niña events. There is a shorter time-series (1948 onwards) index section and a longer (1870 onwards) one. There are less time series that cover from 1870 to present. Second are time-series plots of various ENSO indices.

There is also a El Niño Dashboard looking at the current time-series values and comparing them to historic El Niño events.

These plots show the current 2020-21 values compared to various indices for seven La Niña events since 1948.
Name Description Current Value vs. Historic
La Niña Events
Latest Value Date

MEI V2

A multi-variate index of ENSO which uses SST, winds, SLP, and OLR. It is calculated using the JRA55 reanalysis dataset and the NCEI OLR. Produced at NOAA PSL. -0.79 Mar 2021

Niño 4

SST anomalies averaged over the NINO4 region 5°North-5°South; 160°East-150°West (western most of Niño indices). Total SSTs also available for this region. Calculated from the Monthly NOAA ERSST V5 (at NOAA/CPC). -0.70 Mar 2021

Niño 3.4

SST anomalies averaged over the NINO34 region 5°North-5°South;170-120°West. Total SSTs also available for this region. Correlates well with teleconnections to North America. Calculated from the Monthly NOAA ERSST V5 (at NOAA/CPC). -0.82 Mar 2021

Niño 3

SST anomalies averaged over the NINO3 region 5°North-5°South;150°West-90°West. Total SSTs also available for this region. Calculated from the Monthly NOAA ERSST V5 (at NOAA/CPC). -0.71 Mar 2021

Niño 1.2

SST anomalies averaged over the NINO1 and NINO2 regions 0-10°South;90°West-80°West (eastern most of the Niña indices). Total SSTs also available for this region. Calculated from the Monthly ERSST V5 (at NOAA/CPC). -0.83 Mar 2021

ONI

Oceanic Niño Index: 3 month running mean of ERSST.v4 SST anomalies in the Niño 3.4 region (5°N-5°S, 120°-170°W) Calculated from the ERSST V5 (at NOAA/CPC). -0.94 Feb 2021

BEST

Bivariate El Nino- Southern Oscillation Index: The Niño 3.4 SST and SOI are normalized and combined. SST is from the HadISST1.1. SOI is from NOAA/CPC. Produced at NOAA PSL. -1.86 Dec 2020

SOI

Southern Oscillation Index: Difference between standardized Darwin and standardized Tahiti surface pressure values. It represents the atmospheric component of the ENSO. The sign is opposite that of the Nino indices and it is noisier than those indices. From NOAA/CPC 0.60 Mar 2021

TNI

Trans-Niño Index: Standardized Niño 1+2 minus the Niño 4 with a 5 month running mean applied (restandardized). It represents the gradient of the SST in the ENSO region of the tropical Pacific. Calculated from the Monthly HadISST1.1 dataset. -0.48 Oct 2020

PDO

Pacific Decadal Oscillation: leading principal component of monthly SST anomalies in the North Pacific Ocean, poleward of 20N (global SST mean removed). Calculated from the NOAA OISST V1 and V2 (U of Washington). -1.13 Dec 2020

PNA

Pacific NorthAmerican Pattern. The PNA is one of the most prominent modes of extratropical variability in the northern Hemisphere. This version is calculated at NOAA/CPC. It is based on EOF's calculated from monthly anomalies of 500mb height from the NCEP Reanalysis. -1.24 Mar 2021

OLR

Outgoing Longwave Radiation (OLR) area averages over the central equatorial Pacific (160°E-160°W). OLR is a good measure of convection. Negative OLR represents increased convention. Calculated at NOAA/CPC. 1.40 Mar 2021

Heat Content

Tropical Pacific integrated temperature anomalies (0-300m) 160°E–80°W. Calculated at NOAA/CPC from the GODAS dataset. 0.30 Mar 2021

850mb Zonal Winds

850mb zonal wind anomalies averaged over the western tropical Pacific (140E-170W). From NOAA/PSL using the NCEP/NCAR Reanalysis -3.24 Mar 2021

200mb Zonal Winds

200mb Zonal Wind anomalies 2.5S-2.5N; 165W-110W. Calculated at NOAA/PSL from the NCEP/NCAR Reanalysis. 6.85 Mar 2021

ESPI Precip Index

ENSO Precipitation Index. The index is based on rainfall anomalies in two rectangular areas, one in the eastern tropical Pacific (10°S-10°N, 160°E-100°W) and the other over the Maritime Continent (10°S-10°N, 90°E-150°E). The first step of the procedure involves moving a 10° by 50° block around each box; the minimum and maximum values of all possible blocks is obtained for each box and these are combined to estimate an El Niño precipitation index (EI) and a La Niña precipitation index (LI). The EI and LI are in turn combined to create the ESPI index. Finally, the ESPI index is normalized to have zero mean and unit standard deviation. Calculated at UMD. -1.13 Jan 2021
These plots show the current event values of various indices vs 9 events since 1870.
Name Description Current value vs Historic La Niiño Events Latest Value Date

Niño 4

SST anomalies averaged over the NINO4 region 5°North-5°South; 160°East-150°West (western most of Niño indices). Total SSTs also available for this region. Calculated from the Monthly NOAA ERSST V5 (at NOAA PSL). Climatology 1981-2010. -0.70 Nov 2020

Niño 3.4

SST anomalies averaged over the NINO34 region 5°North-5°South;170-120°West. Total SSTs also available for this region. Correlates well with teleconnections to North America. Calculated from the Monthly NOAA ERSST V5 (at NOAA PSL). Climatology 1981-2010. -1.13 Nov 2020

Niño 3

SST anomalies averaged over the NINO3 region 5°North-5°South;150°West-90°West. Total SSTs also available for this region. Calculated from the Monthly NOAA ERSST V5 (at NOAA PSL). Climatology 1981-2010. -1.14 Nov 2020

Niño 1.2

SST anomalies averaged over the NINO1 and NINO2 regions 0-10°South;90°West-80°West (eastern most of the Niña indices). Total SSTs also available for this region. Calculated from the Monthly NOAA ERSST V5 (at NOAA PSL). Climatology 1981-2010. -0.83 Nov 2020

TNI

Trans-Niño Index: Standardized Niño 1+2 minus the Niño 4 with a 5 month running mean applied (restandardized). It represents the gradient of the SST in the ENSO region of the tropical Pacific. Calculated from the Monthly HadISSTV1.1 dataset. -0.44 Oct 2020
These plots show time-series plots of the monthly values from 1948 to present for the set of ENSO indices.
Name Description Time Series Latest Value Units Latest dateGet Values

MEI V2

A multi-variate index of ENSO which uses SST, winds, SLP, and OLR. It is calculated using the JRA55 reanalysis dataset and the NCEI OLR. Produced at NOAA PSL. -0.79 sigma Mar 2021 Get

Niño 4

SST anomalies averaged over the NINO4 region 5°North–5°South; 160°East–150°West (western most of Nino indices). Total SSTs also available for this region. Calculated from the Monthly ERSST V5 (at NOAA/CPC). -0.70 °CMar 2021 Get

Niño 3.4

SST anomalies averaged over the NINO34 region 5°North-5°South;170-120°West. Total SSTs also available for this region. Correlates well with teleconnections to North America. Calculated from the Monthly ERSST V5 (at NOAA/CPC). -0.82 °C Mar 2021 Get

Niño 3

SST anomalies averaged over the NINO3 region 5°North–5°South; 150°West–90°West. Total SSTs also available for this region. Calculated from the Monthly ERSST V5 (at NOAA/CPC). -0.71 °C Mar 2021 Get

Niño 1+2

SST anomalies averaged over the NINO1 and NINO2 regions 0-10°South; 90°West–80°West (eastern most of the Niña indices). Total SSTs also available for this region. Calculated from the Monthly ERSST V5 (at NOAA/CPC). -0.83 °C Mar 2021 Get

ONI

Oceanic Niño Index: 3 month running mean of ERSST.v4 SST anomalies in the Niño 3.4 region (5°N–5°S, 120°&8211;170°W) Calculated from the ERSST V5 (at NOAA/CPC). -0.94 °C Feb 2021 Get

BEST

Bivariate El Nino- Southern Oscillation Index: The Niño 3.4 SST and SOI are normalized and combined. SST is from the HadISST1.1 SOI is from NOAA/CPC. Produced at NOAA PSL. -1.86 diff std Dec 2020 Get

SOI

Southern Oscillation Index: Difference between standardized Darwin and standardized Tahiti surface pressure values. It represents the atmospheric component of the ENSO. The sign is opposite that of the Nino indices and it is noisier than those indices. From NOAA/CPC 0.60 diff std Mar 2021 Get

TNI

Trans-Niño Index: Standardized Niño 1+2 minus the Niño 4 with a 5 month running mean applied (restandardized). It represents the gradient of the SST in the ENSO region of the tropical Pacific. Calculated from the Monthly HadISST1.1 dataset. -0.48 sigma Oct 2020 Get

PDO

Pacific Decadal Oscillation: leading principal component of monthly SST anomalies in the North Pacific Ocean, poleward of 20N (global SST mean removed). Calculated from the NOAA OISST V1 and V2 (U of Washington). -1.13 sigma Dec 2020 Get

PNA

Pacific NorthAmerican Pattern. The PNA is one of the most prominent modes of extratropical variability in the northern Hemisphere. This version is calculated at NOAA/CPC. It is based on EOF's calculated from monthly anomalies of 500mb height from the NCEP Reanalysis. -1.24 sigma Mar 2021 Get

OLR

Outgoing Longwave Radiation (OLR) area averages over the central equatorial Pacific (160°E–160°W). OLR is a good measure of convection. Negative OLR represents increased convention. Calculated at NOAA/CPC. 1.40 sigma Mar 2021 Get

Heat Content

Tropical Pacific integrated temperature anomalies (0-300m) 160°E-–0°W. Calculated at NOAA/CPC from the GODAS dataset. 0.30 °C Mar 2021 Get

200mb U

200mb Zonal Wind anomalies (2.5°S–2.5°N; 165°W–110°W). Calculated at NOAA PSL from the NCEP R1 dataset. 6.85 °C Mar 2021 Get

ESPI Precip Index

ENSO Precipitation Index. The index is based on rainfall anomalies in two rectangular areas, one in the eastern tropical Pacific (10°S-10°N, 160°E-100°W) and the other over the Maritime Continent (10°S-10°N, 90°E-150°E). The first step of the procedure involves moving a 10° by 50° block around each box; the minimum and maximum values of all possible blocks is obtained for each box and these are combined to estimate an El Niño precipitation index (EI) and a La Niña precipitation index (LI). The EI and LI are in turn combined to create the ESPI index. Finally, the ESPI index is normalized to have zero mean and unit standard deviation. Calculated at UMD. -1.13 SIGMAJan 2021 Get
These plots show time-series plots of the monthly values from 1870 to present for the set of ENSO indices.
Name Description Time Series Latest Value Units Latest date Get Values

Niño 4

SST anomalies averaged over the NINO4 region 5°North-5°South; 160°East-150°West (western most of Nino indices). Total SSTs also available for this region. Calculated from the Monthly ERSST V5 (at NOAA PSL). -0.70 sigma Nov 2020 Get

Niño 3.4

SST anomalies averaged over the NINO34 region 5°North-5°South;170-120°West. Total SSTs also available for this region. Correlates well with teleconnections to North America. Calculated from the Monthly NOAA ERSST V5 (at NOAA PSL). Climatology 1981-2010. -1.13 sigma Nov 2020 Get

Niño 3

SST anomalies averaged over the NINO3 region 5°North-5°South;150°West-90°West. Total SSTs also available for this region. Calculated from the Monthly NOAA ERSST V5 (at NOAA PSL). Climatology 1981-2010.

-1.14 sigma Nov 2020 Get

Niño 1+2

SST anomalies averaged over the NINO1 and NINO2 regions 0-10°South;90°West-80°West (eastern most of the Nina indices). Total SSTs also available for this region. Calculated from the Monthly NOAA ERSST V5 (at NOAA PSL). Climatology 1981-2010. -0.83 sigma Nov 2020 Get

TNI

Trans-Niño Index: Standardized Niño 1+2 minus the Niño 4 with a 5 month running mean applied (restandardized). It represents the gradient of the SST in the ENSO region of the tropical Pacific. Calculated from the Monthly HadISSTV1.1 dataset. -0.44 sigma Oct 2020 Get