Calculated from the HadISST1. It is the area averaged SST from 5S-5N and 170-120W.

Time Interval: Monthly
Time Coverage: 1870 to Sep 2021
Update Status: Periodically updated

Get Data:

Niño 3.4 (anomaly; 1981-2010 mean removed): Standard PSL Format (What is standard format?)
Niño 3.4: Standard PSL Format (What is standard format?)

Source:
Data is from PSL using the HadISST1 dataset.
References:

1. Rayner N. A., D. E. Parker, E. B. Horton, C. K. Folland, L. V. Alexander, D. P. Rowell, E. C. Kent, A. Kaplan, Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century, J. Geophys. Res., 108 (D14), 4407, doi:10.1029/2002JD002670, 2003.

This page hosted by: NOAA Physical Sciences Laboratory (webmaster.psl@noaa.gov) http://psl.noaa.gov/gcos_wgsp/Timeseries/Nino34/index.html