This set of data includes four potential annual recharge grids for the State of Maine that were simulated using the Maine Soil-Water-Balance model for 1991 through 2015. The files include a grid representing the uncertainty in the potential recharge and a grid showing the annual average precipitation from the climate dataset that the simulation is based on. A 25-year simulation of potential recharge to groundwater from the Maine Soil-Water-Balance model for the years 1991 to 2015 produced annual results from which the four potential recharge grids were derived. The four are: 25-year mean, median, maximum, and minimum simulated annual potential. A data exclusion zone (see Scientific Investigations Report 2019–5125) has been applied to the recharge datasets, resulting in a dataset that covers most, but not all, of the State of Maine. The potential recharge grids are given in units of inches per year, with a raster grid cell size of 250 meters. The uncertainty in the simulated grid values is the standard deviation grid, which represents the standard deviation of the simulated median recharge grid. The precipitation data used in the 25-year simulation are from DayMet version 3 daily data. The average annual precipitation grid is the calculated annual average from those data. Further details about the generation and application of the data can be found in Scientific Investigations Report 2019–5125.