This dataset contains the calibrated data of Distributed Temperature Sensing (DTS) measurements conducted at Signy in November 2017, April 2018, September 2018 and September 2019. In this study, we investigate the potential of Active-Distributed Temperature Sensing (DTS) methods for measuring and mapping hyporheic flow in a lowland stream, by burying a few hundred meters of heatable Fiber-Optic (FO) cables within streambed sediments. Active-DTS method can provide high-resolution measurements of saturated flow. Active-DTS methods rely on heating of a FO cable while monitoring the resulting temperature rise at high spatial and temporal resolution. When the method is applied in saturated porous media, the temperature increase, resulting from the artificial heat injection, dependent on the water flux. Conducting Active-DTS in Signy showed that hyporheic fluxes vary by an one order of magnitude. The absence of correlation between water and streambed topography variations suggests that the spatiotemporal variability of fluxes may be used as a marker of the variability of streambed hydraulic conductivities. Here, the relatively low spatial variability in hyporheic flow suggests a small variability of streambed properties.