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HadEX3: Gridded land surface extremes indices

The dataset contains land-based climate extremes produced through the coordination of the joint WMO CCl/WCRP/JCOMM Expert Team on Climate Change Detection and Indices (ETCCDI) and the WMO Expert Team on Sector-specific indices (ET-SCI). It currently comprises of over 80 indices of temperature and precipitation on a 1.25° x 1.875° grid from 1901 to 2018. The indices represent seasonal and/or annual values derived from daily station data. Data are calculated using the Climpact2 software, or have been submitted to the project as pre-calculated indices.

Brief description of the data

Data have been supplied either as calculated indices or as timeseries of Tmax, Tmin and daily precipitation accumulations for each station. These data have been standardised, and for each index, the stations with sufficient data and coverage selected for inclusion in the dataset. A number of quality control checks are applied to test for reasonable values, for issues in the metadata and for duplicate stations (which may have been submitted via two different input data collections). We use the Angular Distance Weighting gridding method, which combines weighted averages of stations within a decorrelation length scale of a grid box centre. Final output netCDF files are produced, containing the annual, and where appropriate, monthly gridded fields.

We automatically produce a number of plots and diagnostics as part of the creation scripts, and these are also available (ETCCDI, ET-SCI). However, as these have been created automatically, not all have been checked and so e.g. colour-scales may not be the most appropriate.

The current version is 3.0.4 (7th January 2022 for ETCCDI, extended 14th March 2024 for ET-SCI indices). For full details see the Changelog.

HadEX3 is also available at CEDA Archive (Centres for Environmental Data Analysis): HadEX3 at CEDA.

Keep in touch

Follow us on twitter: @metofficeHadOBS for updates, news and announcements.

For more detailed information, follow our HadEX blog. Here we describe bug fixes, routine updates and other exploratory analysis.

Please get in touch if you have any feedback on the data files or plots.

Figure shows the distribution of HadEX3 stations for TXx (top), and TXge30 (bottom), both for annual indices.


HadEX3 station locations

Go to download page Data are available from the download page without charge under the Open Government License. Please read the terms and conditions.


When using the dataset in a paper, the following are possible citations to use.

Dunn, R. J. H., et al. (2024), Observed global changes in sector-relevant climate extremes indices - an extension to HadEX3, ESS 11, e2023EA003279

Dunn, R. J. H., Donat, M. G. and Alexander, L. V. (2022), Comparing extremes indices in recent observational and reanalysis products, Frontiers, 4

Dunn, R. J. H., et al. (2020), Development of an updated global land in-situ-based dataset of temperature and precipitation extremes: HadEX3, JGR-A, 125, e2019JD032263

HadEX3-ETSCI station locations

Product User Guide

An introduction to the data set is available as a pdf, which includes a "quick start" guide as well as more in depth material.

Commercial and media enquiries

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Dataset produced in collaboration with:

    Office University of New South Wales NOAA-NCDC Pacific Climate Impacts Consortium Environment Canada WCRP