This dataset contains projected climate data (precipitation, maximum temperature, minimum temperature) from 27 climate scenarios used as input to the Precipitation-Runoff Modeling System (PRMS), and baseline PRMS simulated streamflow at 63 sites in the Upper Rio Grande Basin under each of the 27 scenarios. Projected climate data, obtained from the USGS South Central Climate Adaptation Science Center (Wooten, 2020), were generated using three general circulation models, run under three emission scenarios (RCP 2.6, RCP 4.5, RCP 8.5), and downscaled using three different methods (delta SD, equidistant quantile mapping, piecewise asynchronous regression). Together, the three models, RCPs, and downscaling methods resulted in a set of 27 climate projections. Each input climate data file includes precipitation, maximum temperature, and minimum temperature for each hydrologic response unit in the PRMS model. Model output includes 27 files of PRMS simulated projected daily streamflow at 63 sites in the Upper Rio Grande Basin in Colorado, New Mexico, and Texas for the years 1981-2099.