This dataset consists of time series and evaluation metrics (in comma-separated value format [.csv]) which are described in the Bock and others (2018) Advances in Water Resources research article “Quantifying uncertainty in simulated streamflow and runoff from a continental-scale monthly water balance model.” In this paper, uncertainty was quantified in simulated monthly runoff produced by a monthly water balance model for gaged and ungaged locations across the conterminous United States. The compressed folder UI_byGage.zip contains two files. The file UI_byGage.csv contains the monthly time-step uncertainty intervals and measured and simulated time series of streamflow developed at 1,575 streamgages across the conterminous United States (CONUS). The period of record varies by streamgage. The file Met_byGage.csv contains three metrics (coverage ratio, average width index, and interval skill score), which are evaluations of the uncertainty interval at each of the streamgages. The compressed folder RUN_byHRU.zip contains simulated runoff for 109,951 hydrologic response units (HRUs) across the CONUS. Files are organized by ninteen hydrologic regions (NHDPlus, 2010) and available at a monthly time-step from January 1949 through December 2010. The compressed folder UI_byHRU.zip contains uncertainty intervals (rXX_High.csv and rXX_Low.csv) bounding the simulated runoff at the HRUs. The files have naming conventions and formats identical to the files in the RUN_byHRU.zip folder. The file AWI_byHRU.csv is the average width index calculated for each HRU. See Bock and others (2018) for a full description of the data and metrics.