This dataset contains selected basin characteristics from the GAGES-II dataset (https://water.usgs.gov/lookup/getspatial?gagesII_Sept2011) that were considered for use in regression equations for predicting flow-duration curves as well as additional variables that were constructed or derived from these basin characteristics. Descriptions of basin characteristics used in regression equations are provided (BCdescriptions.xlsx). Additional processing of the selected basin characteristics was done on a region-by-region basis, including deletion of variables with a large (greater than 50%) fraction of the same value (usually zero). A table indicating the basin characteristics considered for use in regression equations for each study region is provided (BCs_byRegion.xlsx). After transformation to reduce skewness and to convert to a similar range of values, these basin characteristics were used to fit regression equations for predicting FDCs. Basin characteristic selection and transformation were performed separately for each study region using all the USGS streamgages that were identified as being of “reference” quality in the GAGES-II dataset. Of the reference quality streamgages, only those having at least 10 complete water years (WYs) during the study period from WY1981 through WY2013 were used in regression model building; these are identified in the dataset. The basin characteristics are presented in their original units (unstransfBCs.new.xlsx) and as transformed (transfBCs.new.xlsx); a table specifying the transformations is provided (tranfBC_info.new.xlsx). Methods are fully described by Over and others (in review).