HadEX3-ETSCI is a land-surface dataset of climate extremes indices available on a 1.875 x 1.25 longitude-latitude grid. The indices in this extension to HadEX3 are those which are recommended by the World Meteorological Organization (WMO) Expert Team on Sector-specific Climate Indices (ET-SCI). Daily precipitation, as well as maximum and minimum temperature observations, are used to calculate these indices at each station. The daily data, as well as indices, have been supplied, quality controlled and combined to make a gridded set of NetCDF files covering 1901-2018 (inclusive). There are minor changes in the input data and also quality control checks which have been included in this dataset which are different to those in HadEX3, version 3.0.4, which contains parameters as defined by the World Meteorological Organization (WMO) Expert Team on Climate Change Detection and Indices (ETCCDI).

Spatial coverage is determined by the number of stations present at each time point as well as the spatial correlation structure between the stations for each index. The spatial coverage is lowest at the beginning of the dataset, rising until around 1960 where it plateaus, and then declines slightly after 2010.

Indices are available as annual and/or monthly quantities. A number of the indices use a reference period to determine thresholds. For these, we provide two versions, one set using 1961-1990 and another using the more recent 1981-2010 (these reference periods have been indicated in the file name as either 'ref-6190' or 'ref-8110').

To align this extension with the existing ETCCDI indices in HadEX3, we commence versioning at 3.0.4.