This is the second digital release of the UK geothermal catalogue of temperature measurements, thermal conductivity measurements and heat flow calculations. This second release contains 1098 new sites alongside 36 sites from the legacy geothermal catalogue. These 36 sites from the legacy catalogue were not included in the first digital release in 2024 due to IPR considerations. This is a 150% increase in the number of sites in the second digital geothermal catalogue release compared to first release. The majority of the new sites are derived from three sources: - New thermal conductivity data collected by the BGS Thermal Conductivity Lab - Datasets synthesised in BGS publications on heat pumps and for subsurface temperature maps - Bottom hole temperature dataset compiled by the UK Onshore Geophysical Library In addition to the new sites, work has been undertaken to better attribute the data source. This indicates where the data came from, be it a report, personal communication, paper etc. Further details can be found in the accompanying report: https://nora.nerc.ac.uk/id/eprint/541614 Dataset DOI: https://doi.org/10.5285/9c324699-abf1-4412-abf9-39308507082d