This dataset consists of refractory black carbon (rBC) mass and number size distributions of snow and firn samples from West Antarctica collected in the 2014-2015 austral summer. An extended-range Single-Particle Soot Photometer (SP2) coupled to a Marin-5 nebulizer was used to measure the size distributions in the Department of Geological Sciences, Central Washington University, WA, USA. The SP2 was calibrated using Aquadag and a Centrifugal Particle Mass Analyzer for BC particles ranging from 0.5 to 800 fg. We present our results as three groups: mass and number distribution for the full core, for the wet season and for the dry season. Wet and dry season subsets are a result of grouping individual samples in 94 seasonally resolved clusters (wet season subset = summer/fall, 474 samples and 47 clusters; dry season subset = winter/spring, 530 samples and 47 clusters). The number of clusters is due to the estimated dating of the core (47 years). The size distributions for the full core is the result of grouping and averaging the 94 clusters together.