This dataset contains two gridded potential evapotranspiration variables for Great Britain from 1961-2019: daily total potential evapotranspiration (PET; kg m-2 d-1) and daily total potential evapotranspiration with interception correction (PETI; kg m-2 d-1). The variables were calculated from the Climate Hydrology and Ecology research Support System meteorology dataset for Great Britain (1961-2019) [CHESS-met] gridded observed meteorological data at 1 km resolution. The units kg m-2 d-1 are equivalent to mm d-1. The data are provided in gridded NetCDF files. There is one file for each variable, for each calendar month. Full details about this dataset can be found at https://doi.org/10.5285/bcec9c33-f863-464e-ac28-73b981bd40a4
