Climate Indices

Climate indices are simple diagnostic quantities that are used to characterize an aspect of a geophysical system such as a circulation pattern. They track droughts, ENSO events, wind patterns, internal modes of climate variability, and extreme events like wildfires and heatwaves. Climate indices play a key role in climate monitoring and prediction. The climate index overview page summarizes the philosophy of climate indices.

To find a specific climate index, jump to the search box below or click your desired index from among the blue sub-category buttons.

To see only the indices with in-depth commentary, select the "Datasets with guidance" button when using the search box.

Dataset Overviews

Climate datasets

Has expert guidance
Nino SST Indices (Nino 1+2, 3, 3.4, 4; ONI and TNI) Nino SST Indices (Nino 1+2, 3, 3.4, 4; ONI and TNI)

  • Years of Record

  • 1870-01 to 2023-04

There are several indices used to monitor the tropical Pacific, all of which are based on sea surface temperature (SST) anomalies averaged across a given region. …

Main variables and Earth System components

Ocean SST - sea surface temperature
Overview: Climate Indices Overview: Climate Indices

  • Years of Record

A climate index is a simple diagnostic quantity that is used to characterize an aspect of a geophysical system such as a circulation pattern. A variety of methods have been…

Main variables and Earth System components

Atmosphere Ocean

  • Experts contributing reviews

  • N/A
Pacific Decadal Oscillation (PDO): Definition and Indices Pacific Decadal Oscillation (PDO): Definition and Indices

  • Years of Record

  • 1900-01 to 2015-12

The Pacific Decadal Oscillation (PDO) is defined by the leading pattern (EOF) of sea surface temperature (SST) anomalies in the North Pacific basin (typically, polewards of…

Main variables and Earth System components

Ocean SST - sea surface temperature