Global ~50km surface water quality data from the dynamical surface water quality model (DynQual). Output data are provided at daily, monthly and annual temporal resolution for the time-period 1980-2019, and include: Water temperature (K) Total dissolved solids (TDS) concentration (mg l-1); an indicator of salinity Biological oxygen demand (BOD) concentration (mg l-1); an indicator of organic pollution Fecal coliform (FC) concentration (cfu 100ml-1); a coarse indicator of bacterial or pathogen pollution Simulations were originally made at 5-arcmin resolution and aggregated to 0.5 degree by summing the in-stream (routed) loadings and channel storage over the aggregated area (at daily, monthly and annual timesteps), and re-calculating in-stream concentrations. A minimum discharge threshold of 0.1 m3 s-1 was used when computing TDS, BOD and FC concentrations, as uncertainties in absolute values of water availabilities have large impacts on resulting in-stream concentrations. Concentrations in these gridcells are assigned as NA. Please note the aggregation technique is provisional and thus the data is subject to change.