This is a dataset of environmental data, percentage vegetation cover, total invertebrate abundance, and mean invertebrate body mass, sampled at 96 soil habitat patches in the Hengill geothermal valley, Iceland, in July 2013. The habitat patches span a temperature gradient of 7-38 degrees C, yet they occur within 2 km of each other and have similar soil moisture, pH, total carbon, and total nitrogen. Effects of soil temperature on the structure and diversity of plant and invertebrate communities using this dataset are presented in Robinson et al. (2018), published in the Journal of Animal Ecology. Full details about this dataset can be found at https://doi.org/10.5285/0f074839-1630-4ccd-aa63-84d0da16b28a