The first dataset contains soil respiration and soil moisture data measured in a semi-arid temperate grassland. We studied the effect of an extreme (5-month) experimental drought and the subsequent watering or drought treatments on soil moisture at 0-30 cm soil depth, and on soil respiration. We also analysed the legacy effect of extreme drought on soil respiration in the next years after the extreme drought treatment, and if it was affected by post-drought precipitation regime. The soil dataset includes soil properties investigated on air-dried soil samples, taken from 0-10 cm soil depth. The investigations were made in a standard laboratory (Institute for Soil Sciences, Centre for Agricultural Research), according to the relevant Hungarian standards (Magyar Szabvány: MSZ).