The potential evapotranspiration (PET) is derived from the air temperature, specific humidity, downward long- and shortwave radiation and surface air pressure from the Climate hydrology and ecology research support system Climate hydrology and ecology research support system meteorology dataset (CHESS-met) data set (https://doi.org/10.5285/835a50df-e74f-4bfb-b593-804fd61d5eab) using a version of the Penman-Monteith equation parameterised for Food and Agriculture Organisation (FAO)-defined well-watered grass. The potential evapotranspiration with interception correction (PETI) is derived from all of the above, plus the (CHESS-met) precipitation, which is the Gridded estimates of daily and monthly areal rainfall for the United Kingdom (CEH-GEAR) precipitation (https://doi.org/10.5285/dbf13dd5-90cd-457a-a986-f2f9dd97e93c) scaled to appropriate units. The PETI calculation adds a correction for interception by a well-watered grass on rain days.

Gridded potential evapotranspiration over Great Britain for the years 1961-2019 at 1 km resolution. This dataset contains two potential evapotranspiration variables calculated using the Penman-Monteith equation parameterised for well-watered short grass: daily total potential evapotranspiration (PET; kg m-2) and daily total potential evapotranspiration with interception correction (PETI; kg m-2). The data are provided in gridded netCDF files. There is one file for each variable for each month of the data set. This research has been carried out under national capability funding as part of the NERC Hydro-JULES programme (NE/S017380/1) and under the NERC Changing Water Cycle program (NE/I006087/1)