This dataset contains hourly automatic weather station (AWS) and 15 minute river flow gauging station data from sites in the Plynlimon (Pumlumon) area of upland mid-Wales, representing the headwaters of the Rivers Severn (Hafren) and Wye (Gwy). A range of instrumentation across 6 AWS sites and 10 gauging stations delivered meteorological and river flow data from 1968 to 2010 to explore changing hydrometeorology as part of the long-term Plynlimon catchment monitoring study. The dataset includes: air temperature, temperature depression, Vapour Pressure Deficit (VPD), precipitation, solar radiation, net radiation, wind speed, wind direction, and river flow. Full details about this dataset can be found at https://doi.org/10.5285/a815235d-6ae1-4e5a-b5cd-138455607cd1
