The GPM Ground Validation Autonomous Parsivel Unit (APU) Wallops Flight Facility (WFF) dataset consists of precipitation data including precipitation amount, precipitation rate, reflectivity in Rayleigh regime, liquid water content, drop diameter, and drop concentration obtained from six Autonomous Parsivel Units (APUs) positioned at the Wallops Flight Facility (WFF) in support of the Global Precipitation Mission (GPM). The APU is an optical laser-disdrometer based on single particle extinction that measures particle size and fall velocity. It consists of the Parsivel2 developed by OTT in Germany and supporting hardware developed by University of Alabama. Data are available in ASCII format for the period of May 6, 2013 through October 9, 2014.