The Cloud Radar System (CRS) WHyMSIE dataset consists of calibrated radar reflectivity, Doppler velocity, linear depolarization ratio, and normalized radar cross-section estimates collected by the Cloud Radar System (CRS) onboard the NASA ER-2 high-altitude research aircraft. These data were collected during the Westcoast and Heartland Hyperspectral Microwave Sensor Intensive Experiment (WHyMSIE) field campaign. WHyMSIE aimed to capture a wide variety of thermodynamic, moisture, and planetary boundary layer regimes across a variety of surface types. The ER-2 flew over a variety of land and ocean environments. Comparing hyperspectral microwave retrievals from CoSMIR-H with in situ temperature and humidity information will allow for scientific advancement of remote-sensing techniques into the hyperspectral microwave era and improved understanding of the planetary boundary layer at different measurement scales. The CRS WHyMSIE dataset files are available from October 22, 2024 through November 4, 2024 in HDF-5 format.