The Global Historical Climatology Network hourly (GHCNh) is a next generation hourly/synoptic dataset that replaces the Integrated Surface Dataset (ISD). GHCNh consists of hourly and synoptic surface weather observations from fixed, land-based stations.
This dataset is compiled from numerous data sources maintained by NOAA, the U.S. Air Force, and many other meteorological agencies (Met Services) around the world. These sources have been reformatted into a common data format and then harmonized into a set of unique period-of-record station files, which are then provided as GHCNh.
How do I access and order GHCNh data?
Search and Order
Use the Dataset Search tool or Interactive Map to find GHCNh stations in a specific region or stations with a specific variable. The interactive map is best for location based searches, while the Dataset search is a good option for mobile devices or assistive technology such as a screen reader. Both tools allow you to order certified PDFs.
Bulk Download
Download GHCNh data for specific years or locations in PSV or parquet format. We recommend this access for large volumes of data.
Please note: NCEI can only certify PDF files accessed via the search and order tools.
Related Products
Local Climatological Data Version 2 (LCD v2)
Local Climatological Data Version 2 (LCDv2) reports are concise monthly summaries of hourly, daily, and monthly weather station measurements.
LCDv2Synoptic Summary of the Day Version 2 (SSOD v2)
The Synoptic Summary of the Day offers daily climate summaries computed from the hourly and synoptic reports provided in GHCNh.
SSODv2How and why was GHCNh developed?
GHCNh is NCEI’s next generation hourly/synoptic dataset, replacing the Integrated Surface Dataset (ISD), which has been provided since the early 2000s. GHCNh incorporates essentially the same set of data sources as its ISD predecessor plus more than 100 additional data sources. Some of these new data inputs provide observations for only a small number of stations, whereas others provided by national Meteorology Services may provide data for hundreds or even thousands of stations.
Likewise, some sources contain observations for only one to a few meteorological elements whereas others are much more comprehensive. These elements include wind speed and direction, wind gust, temperature, dew point and/or wet bulb temperature, relative humidity, cloud data, sea level and station level pressure, altimeter setting, present weather, visibility, precipitation amounts for various time periods, and snow depth. A complete list of data sources and parameter definitions is available in the GHCNh documentation file.
GHCNh was developed as part of a collaboration with the Copernicus Programme and partners at Maynooth University with the aim to make historical land and marine surface weather data more easily accessible worldwide. At NCEI, GHCNh was developed to be vertically aligned with its GHCN daily counterpart (GHCNd). This means that, in general, the same GHCN identifiers are used for stations common to the daily and hourly datasets and these identifiers are managed and searchable in NCEI’s Historical Observing Metadata Repository (HOMR) database and NCEI’s Data Access applications.
What is the GHCNh data quality control process?
A general set of quality control checks is applied to a subset of variables after all sources are integrated into a set of unique periods of record station files. These checks are based on those described in Dunn et al. (2016). In addition, GHCNh preserves the Quality Control information of its component sources. These flags are described in the GHCNh documentation folder.
References
R.J.H. Dunn, K.M.Willett, D.E.Parker,and L. Mitchell, 2016: Geosci.Instrum.Method.Data Syst.Discuss., doi:10.5194/gi-2016-9.
