The Conical Scanning Millimeter-wave Imaging Radiometer – Hyperspectral (CoSMIR-H) dataset consists of calibrated and geolocated brightness temperature (TB) measurements collected from the Westcoast & Heartland Hyperspectral Microwave Sensor Intensive Experiment (WH2yMSIE) campaign onboard the NASA ER-2 high altitude research aircraft. CoSMIR-H provides multi-frequency observations between 50 and 191 GHz that can be used to derive temperature profiles, water vapor profiles, cloud properties, and precipitation rate. WH2yMSIE demonstrated measurements from a hyperspectral microwave airborne sensor (CoSMIR-H) that was complemented by other passive (infrared, visible) and active (lidar, radar) sensors onboard the NASA ER-2 aircraft alongside additional lidar sensors and dropsondes on the G-III aircraft. Serving as a future NASA planetary boundary layer (PBL) mission prototype, WH2yMSIE aimed to capture a wide variety of temperature, moisture, and PBL regimes across a variety of surface types to provide synergistic observations for PBL studies from multiple types of sensors. CoSMIR-H data files are available from October 18, 2024, through November 13, 2024, in netCDF-4 format.