Multi-year high frequency (30 min) time series of DOC concentration measured at the outlet of two mountainous peatlands using the fluorescence properties of the organic matter (fDOM sensor).Stream water level and temperature, water table levels and temperatures (from different piezometer plots), precipitation and air temperature are reported as explanatory variables used to build DOC concentration models.This depository integrates low frequency organic carbon concentration data which were used for optical sensors calibrations and tracking the origin of the organic carbon in the peatlands.