You are here

Home

GHCNDEX: Gridded Temperature and Precipitation Climate Extremes Indices (CLIMDEX data)

NCAR Climate Data Guide Image using GHCNDEX data.

GHCNDEX provides gridded, station-based indices of temperature- and precipitation- related climate extremes. It is intended for climate change detection and attribution studies, climate model evaluation, and operational monitoring of extreme climatic events. Twenty-six indices, including daily maximum and minimum temperatures, number of frost days, maximum 1-day precipitation, and growing season length are provided for 1951 to the present at monthly timesteps on a 2.5°x2.5 ° grid. Definitions of these core indices follow recommendations set forth by the CCl/CLIVAR/JCOMM Expert Team on Climate Change Detection and Indices (ETTCCDI). Input data are from the Global Historical Climatology Network (GHCN) Daily station data. Updates are made operationally. The 26 indices are computed for each station, and then the indices are gridded using an angular distance weighting scheme. Compared with the precipitation-based indices, the temperature-based indices generally show larger spatial coherence and large-scale averages that are more robust to sampling gaps. 

Key Strengths:

  • Large number of indices provided calculated with standard, intuitive definitions of extremes
  • Operationally updated

Key Limitations:

  • Global coverage not as complete as other data sets including more station networks
  • No homogenization to account for changes in observing practices, instrumentation, site location or related issues
  • Uneven updating; e.g. European and North American observations updated more regularly than African and South American observations

Years of Record

1951/01 to 2014/02
temporal metadataID:

Formats

Timestep

Monthly

Data Time Period Extended?

yes, data set is extended

Domain

Global

Spatial Resolution

2.5x2.5 degrees

Ocean or Land

Land Only

Missing Data Flag

missing data present

Vertical Levels

Surface Data Set

Input Data

GHCN-Daily station data

Earth system components and main variables

Atmosphere, Maximum Air Temperature, Minimum Air Temperature, Land, Freeze/Thaw

Suggested Data Citation

Donat, M.G., L.V. Alexander, H. Yang, I. Durre, R. Vose, J. Caesar, 2013: Global Land-Based Datasets for Monitoring Climatic Extremes. Bull. Amer. Meteor. Soc., 94, 997–1006. 

Data Access: Please Cite data sources, following the data providers' instructions.

  1. CLIMDEX view and download netCDF or ASCII files

Key Figures

Click the thumbnails to view larger sizes

Thumbnails

Captions
NCAR Climate Data Guide Image using GHCNDEX data. Change in the mean compared with changes in extremes: Top panel, JJA mean temperature change in the NOAA MLOST dataset; middle panel - change in daytime high temperatures, TXx, in GHCNDEX; bottom panel - change in nighttime minimum temperatures, TNx. An increase in nighttime lows is more pronounced than an increase in daytime highs. Credit: NCAR Climate Data Guide (D. Schneider).

Cite this page

National Center for Atmospheric Research Staff (Eds). Last modified 12 Feb 2014. "The Climate Data Guide: GHCNDEX: Gridded Temperature and Precipitation Climate Extremes Indices (CLIMDEX data)." Retrieved from https://climatedataguide.ucar.edu/climate-data/ghcndex-gridded-temperature-and-precipitation-climate-extremes-indices-climdex-data.

Acknowledgement of any material taken from this page is appreciated. On behalf of experts who have contributed data, advice, and/or figures, please cite their work as well.

GHCNDEX: Gridded Temperature and Precipitation Climate Extremes Indices (CLIMDEX data)

GHCNDEX provides gridded, station-based indices of temperature- and precipitation- related climate extremes. It is intended for climate change detection and attribution studies, climate model evaluation, and operational monitoring of extreme climatic events. Twenty-six indices, including daily maximum and minimum temperatures, number of frost days, maximum 1-day precipitation, and growing season length are provided for 1951 to the present at monthly timesteps on a 2.5°x2.5 ° grid. Definitions of these core indices follow recommendations set forth by the CCl/CLIVAR/JCOMM Expert Team on Climate Change Detection and Indices (ETTCCDI). Input data are from the Global Historical Climatology Network (GHCN) Daily station data. Updates are made operationally. The 26 indices are computed for each station, and then the indices are gridded using an angular distance weighting scheme. Compared with the precipitation-based indices, the temperature-based indices generally show larger spatial coherence and large-scale averages that are more robust to sampling gaps. 

1951-01/2014-02

Copyright 2018 UCAR | Contact | Privacy Policy | Terms of Use | Copyright Issues | NCAR Home

The National Center for Atmospheric Research is sponsored by the National Science Foundation. Any opinions, findings and conclusions or recommendations expressed in this material do not necessarily reflect the views of the National Science Foundation.