We present 18 new cosmogenic radionuclide samples collected from modern river sand and dated Holocene terrace and floodplain deposits from the Ganga River at the Himalayan mountain front, which display a notable degree of temporal variability. This variability is explored using field observations and numerical and statistical analysis. We propose that the observed variability is driven by the nature of stochastic inputs of sediment and the evacuation timescales of individual sediment deposits.