The dataset portrays heat flow as a continuous modelled surface, interpolated between observation points. Onshore coverage is provided for England, Wales, Scotland and Northern Ireland. The British Geological Survey (BGS) Heat flow dataset version 1 (United Kingdom) is derived from a catalogue of legacy heat flow observations and ground-heat modelling. Heat flow data is typically used to determine temperatures beneath the ground surface, and model how much thermal energy may be stored in or recovered from the ground. The dataset is presented as a raster model, but is also available as cellular, vector grids. The raster and square-cellular grid defines each cell by an area of c. 4km2 (2km per side). The hexagonal-cellular defines each cell by an area of c. 2.56km2 (1km per side). Heat flow values are milli-Watts per square metre (mWm-2). The data are available under BGS data licence.