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HadEX3: Global land-surface climate extremes indices v3.0.1 (1901-2018)

Update Frequency: Not Planned
Latest Data Update: 2020-09-30
Status: Superseded
Online Status: ONLINE
Publication State: Citable
Publication Date: 2020-10-06
DOI Publication Date: 2020-10-08
Download Stats: last 12 months
Dataset Size: 64 Files | 4GB

This dataset has been superseded. See Latest Version here

HadEX3 is a land-surface dataset of climate extremes indices available on a 1.875 x 1.25 longitude-latitude grid. These 29 indices have been developed by the World Meteorological Organization (WMO) Expert Team on Climate Change Detection and Indices (ETCCDI). 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).

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.

All indices are available as annual quantities, with a subset also available on a monthly basis. 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').

In September 2020, a user identified some issues in the DTR and TN90p (61-90) indices. These were found to have arisen from erroneous values in a few stations which were not picked up by any quality control checks. These stations were noted on the bad list and these two indices re-run, hence v3.0.1.

Citable as:  Dunn, R.J.H.; Alexander, L.; Donat, M.; Zhang, X.; Bador, M.; Herold, N.; Lippmann, T.; Allan, R.J.; Aguilar, E.; Aziz, A.; Brunet, M.; Caesar, J.; Chagnaud, G.; Cheng, V.; Cinco, T.; Durre, I.; de Guzman, R.; Htay, T.M.; Wan Ibadullah, W.M.; Bin Ibrahim, M.K.I.; Khoshkam, M.; Kruge, A.; Kubota, H.; Leng, T.W.; Lim, G.; Li-Sha, L.; Marengo, J.; Mbatha, S.; McGree, S.; Menne, M.; de los Milagros Skansi, M.; Ngwenya, S.; Nkrumah, F.; Oonariya, C.; Pabon-Caicedo, J.D.; Panthou, G.; Pham, C.; Rahimzadeh, F.; Ramos, A.; Salgado, E.; Salinger, J.; Sane, Y.; Sopaheluwakan, A.; Srivastava, A.; Sun, Y.; Trimbal, B.; Trachow, N.; Trewin, B.; van der Schrier, G.; Vazquez-Aguirre, J.; Vasquez, R.; Villarroel, C.; Vincent, L.; Vischel, T.; Vose, R.; Bin Hj Yussof, M.N.A. (2020): HadEX3: Global land-surface climate extremes indices v3.0.1 (1901-2018). Centre for Environmental Data Analysis, 08 October 2020. doi:10.5285/ee378533af6243899bc93653cbd41eaa.
Abbreviation: Not defined
Keywords: HadEX3, indicies, temperature, monthly, annual, land, surface, climate


Previous Info:
No news update for this record
Previously used record identifiers:
No related previous identifiers.
Access rules:
Public data: access to these data is available to both registered and non-registered users.
Use of these data is covered by the following licence: When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Data lineage:

Data were produced by the project team and supplied for archiving at the Centre for Environmental Data Analysis (CEDA).

HadEX3 is a dataset of gridded land-surface temperature and precipitation extremes indices and was produced by the Met Office Hadley Centre in collaboration with the ARC Centre of Excellence for Climate Extremes at the University of New South Wales and many data contributors from institutes and organisations around the world. The extremes indices were developed by the former WMO Expert Team on Climate Change Detection and Indices (ETCCDI) and derived from daily, station-based observations. These have undergone quality control checks and then been blended into a gridded product using an angular distance weighting routine.

Data Quality:
CF-Compliant NetCDF files. The extremes indices have undergone quality control checks at the station level to ensure consistency. These data are quality controlled by the data provider and not the Centre for Environmental Data Analysis (CEDA).
File Format:
Data are provided in NetCDF formats.

Process overview

This dataset was generated by the computation detailed below.

HadEX3 data processing performed at the Met Office Hadley Centre


Data were taken from public-facing archives as well as by submission from co-authors. These came either as precalculated indices or as daily precipitation, maximum and minimum temperatures. Where necessary, the indices were calculated from the daily values using the Climpact2 code, or reformatted to standard outputs. We perform some quality control checks on the indices to identify erroneous values and remove these stations from further use.

In order to calculate the grid-box values, we use the Angular Distance Weighting scheme, which uses a search radius from the grid-box centre to identify stations that could contribute. This search radius is defined by the correlation structure of the station timeseries (a decorrelation length scale) and is determined within latitude bands. If at least three stations within this search radius have data values for a given year/month then the grid-box value is calculated.

Input Description


Output Description


Software Reference


  • units: %
  • long_name: Amount of cold nights
  • var_id: TN10p
  • units: %
  • long_name: Amount of cool days
  • var_id: TX10p
  • units: %
  • long_name: Amount of hot days
  • var_id: TX90p
  • units: %
  • long_name: Amount of warm nights
  • var_id: TN90p
  • units: days
  • long_name: Consecutive Dry Days
  • var_id: CDD
  • units: days
  • long_name: Consecutive Wet Days
  • var_id: CWD
  • units: %
  • long_name: Contribution from extremely wet days
  • var_id: R99pTOT
  • units: %
  • long_name: Contribution from very wet days
  • var_id: R95pTOT
  • long_name: Daily Temperature Range
  • units: degrees_C
  • var_id: DTR
  • units: degrees_C
  • long_name: Extreme Temperature Range
  • var_id: ETR
  • units: days
  • long_name: Growing Season Length
  • var_id: GSL
  • units: days
  • long_name: Ice Days
  • var_id: ID
  • units: mm
  • long_name: Max 5-day PR
  • var_id: Rx5day
  • units: degrees_C
  • long_name: Max TX
  • var_id: TXx
  • units: degrees_C
  • long_name: Min TN
  • var_id: TNn
  • units: days
  • long_name: Number of heavy rain days
  • var_id: R10mm
  • units: days
  • long_name: Number of very heavy rain days
  • var_id: R20mm
  • units: days
  • long_name: Summer days
  • var_id: SU
  • units: mm
  • long_name: Total annual PR from heavy rain days
  • var_id: R95p
  • units: mm
  • long_name: Total annual PR from very heavy rain days
  • var_id: R99p
  • units: mm
  • long_name: Total wet-day PR
  • var_id: PRCPTOT
  • units: days
  • long_name: Tropical nights
  • var_id: TR
  • units: days
  • long_name: Warm spell duration indicator
  • var_id: WSDI
  • var_id: latitude_bnds
  • var_id: longitude_bnds

Co-ordinate Variables

  • units: degrees_north
  • standard_name: latitude
  • var_id: latitude
  • long_name: latitude of grid box centres
  • units: degrees_east
  • standard_name: longitude
  • var_id: longitude
  • long_name: longitudes of grid box centres
  • standard_name: time
  • var_id: time