This data release contains three data types that could potentially be used to infer spatiotemporal variability in groundwater discharge processes, along with other research and monitoring purposes: 1) Temporally continuous stream channel water temperature and adjacent streambank air temperature time series data (generally starting November 2020) as well as limited temperature data from May to October 2022 from select seeps and springs; 2) Discrete stable isotope data collected from stream water (May 2021, October/November 2021, May 2022, October/November 2022); and 3) Discrete dissolved radon gas data from stream water (collected May 2021 and May 2022). Data were collected at 51 temporary stations installed along the east branch, west branch, and mainstem of the Neversink River, along with several perennial tributaries to the primary river branches. Air and stream temperature time-series data vary in spatial and temporal coverage as detailed in README_processed.txt found in the ‘Processed_data’ directory. Output temperature matrices are resampled at a daily timestep. Stable water isotope and radon data were collected at most but not all stream temperature sites, and six hillslope groundwater discharge locations, as detailed in the ‘Raw_data’ directory. Details regarding the specific instrumentation and lab analysis used are listed in the ‘README_raw’ text file located in the ‘Raw_data’ directory. Additionally, the locations of paired stream and air temperature data can be accessed as a shapefile ‘XYTidbits_deployed_final.shp’. Stable isotope data were also collected along the mainstem of the upper Delaware River (starting at Hancock New York) from June 27 to July 1, 2021 for a related project, and those data are also included here in the ‘Raw_data’ directory. Version 3.0 of this release additionally includes 1000-meter upstream drainage areas (Neversink_1000m_wedge.zip) for stream temperature sensors. These polygons may be used to summarize landscape characteristics (e.g., slope, total wetness index, soil type, underlying bedrock type) near monitoring sites to infer spatiotemporal variability in groundwater discharge processes.