The Microwave Atmospheric Sounder on Cubesat (MASC) CPEX dataset contains products obtained from the MASC instrument onboard the DC-8 aircraft. These data were collected in support of the NASA Convective Processes Experiment (CPEX) field campaign. The CPEX field campaign took place in the North Atlantic-Gulf of America-Caribbean Sea region from 25 May-25 June 2017. CPEX conducted a total of sixteen DC-8 missions from 27 May-24 June. The CPEX campaign collected data to help explain convective storm initiation, organization, growth, and dissipation in the North Atlantic-Gulf of America-Caribbean Oceanic region during the early summer of 2017. These data are available from May 27, 2017 through June 21, 2017 and are available in HDF-5 format.