This dataset contains flammability metrics for fuel types that are commonly involved in wildfires in the UK. Flammability data were obtained by cone calorimetry, and include measures of ignitibility (time to ignition), peak heat release rate, total heat release, and effective heat of combustion. The dataset contains the results of 1634 tests on 833 fuel samples, with 801 of these being tested in duplicate. Samples were obtained between January 2021 and October 2023 from 22 sites across Great Britain. Calorimetry data are matched to weather data obtained at times of sampling, and fuel moisture contents obtained by weighing samples before and after drying. The data will be used to assess comparative fire risk between vegetation types, and to refine inputs for fire behaviour modelling. Full details about this dataset can be found at https://doi.org/10.5285/45af9c3d-999d-44dd-83fc-b4d81632967d