Data showing groundwater temperature and levels from bore holes are presented. The data were collected from a field experiment in the Conwy catchment between December 2013 and June 2015. Data were recorded by pressure transducers installed in the bore holes. The data were collected by trained members of staff from Bangor University and the Centre for Ecology & Hydrology. The samples were taken to estimate the hydraulic pathways and velocities through an experimental hillslope. The data were collected for the NERC project 'The Multi-Scale Response of Water quality, Biodiversity and Carbon Sequestration to Coupled Macronutrient Cycling from Source to Sea' (NE/J011991/1). The project is also referred to as Turf2Surf. Full details about this dataset can be found at https://doi.org/10.5285/6c58038e-f035-4ab5-8518-1f189eae3bf2