Climate-mode indices: PDO, ENSO, AO, NAO, PNA, AMO (NOAA)#

climate-indices · theme climate · live

Monthly climate-mode indices from the NOAA offices that maintain them: the PDO and AMO from NCEI (the National Centers for Environmental Information, NOAA’s archive; ERSSTv5), RONI (CPC’s official ENSO index since February 2026), the legacy ONI, Niño 3.4 and relative Niño 3.4, AO, NAO and PNA from CPC (the National Weather Service’s Climate Prediction Center), and MEI.v2 from PSL (the Physical Sciences Laboratory, a NOAA research lab). Interannual context for snowpack and melt timing.

import easysnowdata as esd

aoi = (-121.94, 46.72, -121.54, 46.99)   # Mount Rainier
indices_ds = esd.climate.indices.load(aoi, time="2024-03")

No account needed

Every route to this product is open. Nothing to set up.

Sources#

2 routes serve this product; the first is the default and source= picks another. The return contract is the same either way.

source

provider

credentials

resolution

extent

temporal

latency

notes

noaa (default)

table_http

none

—

global (index time series)

1854- (PDO, AMO); 1950- (CPC); 1979- (MEI.v2)

monthly, by about the 10th

each index from the office that maintains it (NCEI ERSSTv5 PDO/AMO; CPC RONI, ONI, Niño 3.4, AO, NAO, PNA; PSL MEI.v2); the newest CPC ENSO values can be revised for two months

psl

table_http

none

—

global (index time series)

1948- (most); PDO to 2025-08; AMO to 2023-01

monthly; some files no longer updated

PSL’s correlation-page copies, for reproducing work that used them; its PDO and AMO are different series and have stopped, and its ONI splices ERSSTv5 and v6 — not a default

Where each route points#

noaa — NOAA CPC / NCEI / PSL text files live

https://www.cpc.ncep.noaa.gov/data/indices/

psl — NOAA PSL correlation-page files live

https://psl.noaa.gov/data/correlation/

Variables#

variable

units

dtype

nodata

categorical

pdo

1

float64

—

no

roni

degC

float64

—

no

oni

degC

float64

—

no

nino34

degC

float64

—

no

rnino34

degC

float64

—

no

mei

1

float64

—

no

ao

1

float64

—

no

nao

1

float64

—

no

pna

1

float64

—

no

amo

degC

float64

—

no

Provenance#

Licence · public domain (U.S. Government work)

Cite the data as

NOAA Climate Prediction Center (RONI, ONI, Niño 3.4, AO, NAO, PNA); NOAA NCEI ERSSTv5 PDO and AMO indices (Huang et al. 2017, doi:10.1175/JCLI-D-16-0836.1); Wolter & Timlin (2011) and Zhang et al. (2019) for MEI.v2; Mantua et al. (1997) and Newman et al. (2016) for the PDO.

Documentation

Loader · easysnowdata.climate.indices.load