Glaciers influence the runoff regime of the catchments they are located in due to accumulation on to the ice surface in winter and ablation in summer. In this study we estimate the contribution of seasonally delayed glacier melt water to total runoff for current and future climate conditions. We find that the influence of glaciers on total runoff in the highly glaciated catchment of the Rhone river in Valais, Switzerland is high under current climate condi- tions and that a considerable decrease can be expected until year 2085, where it becomes nearly negligible compared to seasonal precipitation fluctuations.