New Version of the Global Historical Climatology Network-Daily Database

NCDC deployed a new version of the Global Historical Climatology Network-Daily (GHCN-Daily) integrated database of daily climate summaries from land surface stations across the globe on June 25, 2012. This new version included 116 new stations and updates for many stations in and around Russia. These new data add approximately 17 million values to the database and significantly increase the amount of data available for studying regional climatological events from the recent past, such as the Russian heat wave of July 2010.

The GHCN-Daily database provides numerous daily variables for thousands of stations all over the world including maximum and minimum temperature, total daily precipitation, snowfall, and snow depth. Both the record length and period of record vary by station and cover intervals ranging from less than a year to more than 175 years, with the average temperature record spanning about 36 years and the average precipitation record lasting about 33 years.

NCDC assigns a unique version identifier to each updated and fully reprocessed copy of the GHCN-Daily and then archives the dataset for potential future retrieval. This identifier consists of two components: a version number which changes, for example, when a new data source is added or a significant change is made to the processing system, and a timestamp that identifies the date and time at which the data set was last reprocessed or updated. With the updates to stations around Russia, the version number component has been incremented from 2.92 to 2.93.

Additionally, a paper entitled “An overview of the Global Historical Climatology Network-Daily Database” was published in the Journal of Atmospheric and Oceanic Technology July edition. Authored by NCDC scientists Matthew Menne, Imke Durre, Russell Vose, Byron Gleason, and Tamara Houston, this paper describes the GHCN-Daily database and the processes in place to maintain and update it.