mHM is a gridded distributed hydrological model developed by the Helmholtz Centre for Environmental Research GmbH (UFZ). It encompasses various processes including canopy interception, snow dynamics (accumulation and melt), soil moisture dynamics, infiltration, surface runoff, evapotranspiration, deep percolation, subsurface storage, baseflow, discharge generation, discharge attenuation, and flood routing. The model’s source code is highly modular and written in Fortran. mHM has been extensively applied in over 1,000 European basins and globally in more than 5,000 GRDC basins, spanning a range of sizes and spatial resolutions from 1 km by 1 km to 100 km by 100 km.