This database was developed in a research study of “Zarei, M., Destouni, G. A global multi catchment and multi dataset synthesis for water fluxes and storage changes on land. Sci Data 11, Nature, 1333 (2024). https://doi.org/10.1038/s41597-024-04203-1”. The data from all comparative datasets are synthesized into a complete new open access database, named the Global HydroClimatic Database (GHCD), and presenting data and information in five separate folders. The zipped file named ‘GHCD Non-Overlapping Catchment Shapefiles.zip’ in Folder 1 contains the study catchment polygon shapefiles, used to extract the associated data from the global datasets and further aggregate them over each catchment to produce the catchment-average data time series. The catchment polygons were obtained from the GSIM database and are renamed according to the catchment names used in the GHCD database. A csv file named ‘Catchment_Info.csv’ in Folder 1 lists the GHCD catchment names, their corresponding name in the GSIM database, the country in which the catchment outlet (hydrometric station) is located, and the catchment area in square kilometers according as reported in the GSIM database. Folders 2-5 provide catchment-aggregated monthly and annual time series for the studied variables (P, ET, R, DS, SM, and T) for the 1561 non-overlapping study catchments and the four comparative “Obs”, “Mixed”, “GLDAS”, and “ERA5” datasets included in GHCD. The catchment-wise data time series are exported as “.csv” files, separately for each variable and catchment. Each Dataset folder contains an (i) Annual folder, (ii) Monthly folder, (iii) “DatasetX_AnnualDataSummary.csv” file, and (iv) “Readme_Data Columns and Variable Units.txt” file. Before using the variable time series in the Annual or Monthly folders, GHCD database users are recommended to read the “Readme_Data Columns and Variable Units.txt” file. This file provides complete information that clarifies the variables included in the Annual and Monthly folders, and the associated data source and origin, variable units, and column names of the time series in the CSV files. For the SM variable, the rootzone depth for the soil moisture profile considered in the associated reanalysis product of the “Mixed” (GLEAM), “ERA5”, and “GLDAS” datasets is also reported for possible further applications. The “DatasetX_AnnualDataSummary.csv” file included in Folders 2-5 also provides brief summary information for all data considered for the 1561 non-overlapping catchments in all comparative datasets included in GHCD. This file also provides catchment-wise long-term average annual values of P, R, ET, DS, DSM, and T for all GHCD catchments. Further this file provides explicit calculated data for the implied CWLC, and also for PETLang, PET/P, ET/P, and R/P as “Quality check data”. The catchment names, the country where the catchment outlet is located, and the catchment area in square kilometers are also provided in this data summary.