These datasets contain sampled fuel moisture content data for vegetation, organic soil and leaf litter as part of the UK Fire Danger Rating System project funded by NERC (NE/T003553/1). The sampled vegetation comprises both live and dead heather, gorse, bracken, moor grass and moss. Where relevant, the canopy/leaves and stem were sampled separately. The datasets also contain associated information about the sample site characteristics (land cover class, elevation, slope and aspect) and meteorological variables (temperature, relative humidity and wind speed at the time of sampling). There are three datasets included which represent three separate studies: (i) UK-wide dataset which contains samples from sites across the UK from 2021-2023; (ii) North Yorkshire Moors dataset which contains samples from the North Yorkshire Moors, where sites were chosen to represent a combination of landscape characteristics, from five days in 2021; (iii) West Midlands dataset which contains samples from multiple volunteers on one day only across two sites. Full details about this dataset can be found at https://doi.org/10.5285/9334118f-3389-4a13-89a1-d75ec6fcc43a