The GPM Ground Validation Cloud Radar System (CRS) OLYMPEX dataset provides radar reflectivity and Doppler velocity data collected during the Olympic Mountain Experiment (OLYMPEX). This dataset is used to estimate cloud droplet distribution for the storms monitored during the field campaign. The CRS instrument is a 94GHz W-band Doppler radar with a 3mm wavelength. CRS can be deployed as both an airborne instrument onboard NASA’s high-altitude science aircraft, the Earth Resource 2 (ER-2), as well as a ground based radar system. Only the airborne mode was used during OLYMPEX. In addition to reflectivity and Doppler velocity, the data files include aircraft flight information. The CRS was flown on 10 different days between November 10, 2015 and December 10, 2015. Each data file contains one hour of flight measurements during flight in UTC time. Files for this dataset are in netCDF-3 format and readily accessible without the need of specialized software.