The GPM Ground Validation CAX1 Radar RB5 format OLYMPEX dataset consists of radar parameters, such as radar reflectivity, Doppler velocity, Doppler width, Differential reflectivity, and signal quality index, provided on a 0.4 to 1.0 km spatial resolution within the OLYMPEX field campaign study region in the state of Washington. These data were obtained for the GPM Ground Validation OLYMPEX field campaign by the SELEX Meteor 60DX10 Compact Weather (CAX1) radar. The CAX1 radar was located at the southern tip of Vancouver Island on the Canadian Forces Base (CFB) Esquimalt Albert Head (AHD) military training area. The CAX1 radar was operated by Environment and Climate Change Canada (ECCC) to support the OLYMPEX field campaign. These data are available in RB5 binary and PNG formats from November 13, 2015 to April 20, 2016.