Observed daily streamflow time series and daily streamflow time series predicted by the statistical methods at GAGES-II (Falcone, 2011) reference basins were obtained from Russell and others (2020). Predicted daily streamflow time series from the NHM-PRMS were obtained from Hay and LaFontaine (2020). The streamflow statistics in this data release were calculated from these observed and predicted streamflow time series and by direct statistical prediction methods as described in the metadata.