The GPM Ground Validation NASA S-Band Dual Polarimetric (NPOL) Doppler Radar IFloodS dataset was collected from April 30 to June 16, 2013 near Traer, Iowa as part of the Global Precipitation Measurement (GPM) mission Iowa Flood Studies (IFloodS) campaign. Officially the IFloodS campaign ran from May 1 to June 15 but the NPOL Doppler radar was installed and calibrated prior to the start, allowing for the wider period of record. The NPOL radar, developed by a research team from Wallops Flight Facility, is a fully transportable and self-contained S-band (10 cm), scanning dual-polarimetric, doppler research radar that collected and operated nearly continuously during the IFloodS field campaign. It takes accurate volumetric measurements of precipitation including rainfall rate, particle size distributions, water content and precipitation type. The NPOL Doppler Radar IFloodS data is available in Universal Format (UF) with browse images available in PNG file format.