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Many researchers could benefit from the use of Global Historical Climatology Network (GHCN) data.  But one of the problems they face with the data (other than downloading and uncompressing/unzipping those monster-size data files) is extracting data from the stations they need.  There is some extraction code available on both GHCN download sites, but it isn't user friendly nor is it completely functional.  Therefore I have reworked an extraction program I developed while at the Tree-Ring Laboratory at Lamont-Doherty Earth Observatory (of Columbia University (in the City of New York)).

According to the World Data Center for Meteorology in Asheville, North Carolina, the GHCN "is a comprehensive global baseline climate data set comprised of land surface station observations of temperature, precipitation, and pressure. All GHCN data are on a monthly basis with the earliest record dating from 1697."

There are two versions of the GHCN.  The initial version, which came out in 1992, contains monthly temperature, precipitation, station pressure and sea-level pressure data.  The second version, GHCN2, contains monthly mean, maximum and minimum temperature and precipitation data.  The temperature data was released in 1997 and the precipitation data was released in 1999.

GHCN (version 1) data can be obtained from the Carbon Dioxide Information Analysis Center.  Follow the links to NDP-041. GHCN2 data can be obtained from the World Data Center for Meteorology in Asheville.  Follow the links to GHCN.  There are some restrictions on international commercial use of the dataset, but there are no restrictions on non-commercial use.  You will have to agree to the terms before gaining access to the data.

I originally had two programs, one for extracting data from GHCN1 files and one for GHCN2 files. I had also supported both 16-bit and 32-bit versions of the ClimExWin programs, but on 23 July 2003 decided to no longer make the 16-bit versions available. On 31 July 2003 I decided to combine GHCN1 and GHCN2 search functions into one program.

The current program is now ClimExWin, which can search and extract data from both GHCN1 and GHCN2 files. ClimExWin is a native 32-bit Windows program. The current version number is 3.2.

To use the program, download the zip file and unzip it into a temporary directory. Run the setup program from the temporary directory and follow its instructions. Contact me if you need any assistance.

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References

GHCN Version 1:

Vose, R. S., Richard L. Schmoyer, Peter M. Steurer, Thomas C. Peterson, Richard Heim, Thomas R. Karl, and J. Eischeid, 1992: The Global Historical Climatology Network: long-term monthly temperature, precipitation, sea level pressure, and station pressure data. ORNL/CDIAC-53, NDP-041. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee.

GHCN Version 2:

Peterson, Thomas C. and Russell S. Vose, 1997: An overview of the Global Historical Climatology Network temperature data base, Bulletin of the American Meteorological Society, 78, 2837-2849.

Peterson, Thomas C., Russell S. Vose, Richard Schmoyer, and Vyachevslav Razuvaev, 1997: Quality control of monthly temperature data: The GHCN experience. International Journal of Climatology, submitted.

Easterling, David R., Thomas C. Peterson, and Thomas R. Karl, 1996: On the development and use of homogenized climate data sets. Journal of Climate, 9, 1429-1434.

Easterling, D.R. and T.C. Peterson, 1995: The effect of artificial discontinuities on recent trends in minimum and maximum temperatures. Atmospheric Research, 37, 19-26.

Easterling, David R. and Thomas C. Peterson, 1995: A new method for detecting and adjusting for undocumented discontinuities in climatological time series. International Journal of Climatology, 15, 369-377.

Peterson, Thomas C. and David R. Easterling, 1994: Creation of homogeneous composite climatological reference series. International Journal of Climatology, 14, 671-679.

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