This dataset contains high-frequency (15-minute interval) in situ observations of soilhydrothermal conditions collected between January 2016 and June 2025 at an agriculturalfield site in the Berambadi/Bechanahalli catchment, Karnataka, southern India. The monitoringsite is representative of semi-arid, monsoon-dominated agroecosystems on the Mysore Plateau. The dataset includes time-synchronized measurements of volumetric soil moisture, soiltemperature, electrical conductivity (EC), relative dielectric permittivity (RDP), andprecipitation. Measurements are available at 5 cm and 50 cm depths throughout the record,with an additional intermediate depth (15 cm) introduced in 2021 to improve verticalresolution. From 2016 to 2020, soil electrical conductivity was measured directly using EC sensors.Beginning in 2021, the monitoring system transitioned to dielectric permittivity sensors.The 2021 overlap period enables continuity of event-scale diagnostics across the sensortransition. Electrical conductivity and dielectric permittivity are reported as distinctvariables and should be interpreted accordingly. All data are provided at their native 15-minute temporal resolution without temporalinterpolation or gap filling. Quality control focused on physical plausibility and sensorconsistency, including removal of physically implausible values, identification of sensorflatlining, and verification of expected depth-dependent variability. Short-lived soilmoisture exceedances above laboratory-derived saturation thresholds were retained and flagged,as these may represent transient surface ponding during intense monsoon rainfall. The dataset is distributed as yearly CSV files and is intended to support analyses ofevent-scale infiltration dynamics, vertical connectivity, thermal coupling, land–surfacemodel evaluation, and satellite soil moisture validation in monsoon-driven semi-arid systems.