NOTICE (March 2018): This website provides access to the CDIAC archive data temporarily. It will be gradually transitioned into data packages in the new ESS-DIVE archive. This site will continue to operate in parallel during and after the transition, and will be retired at a future date. If you have any questions regarding the data or the transition, please contact

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Extended Edited Synoptic Cloud Reports from Ships and Land Stations Over the Globe, 1952-2009 (NDP-026C)

Data graphic Data Files PDF graphic Original NDP-026C Documentation PDF graphic 2012 Updated Documentation

Date of Publication

Original date of publication: August 1999.
Updated March, 2002: This page and the global cloudiness data set updated to reflect the addition of 12 monthly files of ship reports for 1997.
Updated April, 2009: This page and the global cloudiness data set and documentation updated with an additional 11 years (through 2008) of ship reports. Added a new data directory (ship_199801_200812) containing the reports. Please see the new APPENDIX U in ndp026c.pdf for important details regarding record format differences of these new data files.

Updated August, 2012: Formerly titled 'Extended Edited Synoptic Cloud Reports from Ships and Land Stations Over the Globe, 1952-1996 (with Ship data updated through 2008)', this page and the global cloudiness data set and documentation have been updated with an additional 13 years (through 2009) of land-based reports. A new data directory was added (land_199701_200912) containing the reports, but the ship reports data still extend through 2008. Please see the new documentation file NDP-026C_EECRA_Update_1997-2009.pdf for important details on new sources of land data and record format differences in these new data files.


C. J. Hahn
Dept. of Atmospheric Sciences,
University of Arizona

S. G. Warren
Dept. of Atmospheric Sciences,
University of Washington

R. Eastman
Dept. of Atmospheric Sciences,
University of Washington




This database contains surface synoptic weather reports for the entire globe, gathered from various available data sets. The reports were processed, edited, and rewritten to provide a single dataset of individual observations of clouds, spanning the 57 years 1952-2008 for ship data and the 39 years 1971-2009 for land station data. In addition to the cloud portion of the synoptic report, each edited report also includes the associated pressure, present weather, wind, air temperature, and dew point (and sea surface temperature over oceans). This data set is called the "Extended Edited Cloud Report Archive" (EECRA).

The EECRA is based solely on visual cloud observations from weather stations, reported in the WMO synoptic code (WMO, 1974). Reports must contain cloud-type information to be included in the archive. Past data sources include those from the Fleet Numerical Oceanographic Center (FNOC, 1971-1976) and the National Centers for Environmental Prediction (NCEP, 1977-1996). This update uses data from a new source, the 'Integrated Surface Database' (ISD, 1997-2009; Smith et al., 2011). Our past analyses of the EECRA identified a subset of 5388 weather stations that were determined to produce reliable day and night observations of cloud amount and type. The update contains observations only from this subset of stations. Details concerning processing, previous problems, contents, and comments are available in the archive's original documentation .

The EECRA contains about 81 million cloud observations from ships and 380 million from land stations. The data files have been compressed using unix. Unix/linux users can "uncompress" or "gunzip" the files after downloading.

If you're interested in the NDP-026C database, then you'll also want to explore its related data products, NDP-026D and NDP-026E.


  • Smith, A., N. Lott, and R. Vose, 2011: The Integrated Surface Database: Recent developments and partnerships. Bull. Amer. Meteor. Soc., 92, 704-708.
  • WMO, 1974: Manual on Codes. Vol. 1., World Meteorological Organization Publication 306, 348 pp.

Last updated 08/2012