Glaciers are among the most frequently used natural phenomena to illustrate ongoing global warming. Retreating glacier tongues and the reduction of glacierized areas are visible all over the world. Changes in glacier volume affect both the river runoff regime downstream and sea level. In Norway, mountain glaciers and associated streamflow are of particular importance since the electricity sector relies on hydropower. The spatial and temporal distribution of glacier mass-balance and discharge measurements from glacierized catchments is therefore biased towards demands from hydropower utilization. This study investigates glacier mass balance and associated meltwater discharge together with their spatial and temporal variations. A mass-balance model has been adapted to the glacierized area in Norway using temperature and precipitation data from seNorge (http://www.senorge.no) and potential solar radiation as input. The data from seNorge are available for the whole country on a 1 km horizontal grid and on a daily time step from 1957 to present. The gridded data from seNorge are evaluated using winter mass balances at point locations on glaciers in different regions across the country. Results indicate that the seNorge data are suitable for mass-balance modeling, but further adjustment of the precipitation data should be performed. The modeled mass balances for the glacierized area of Norway yield a overview of spatial averaged glacier mass balance from 1961-2010. Seasonal mass balances show large year-to-year variability. Nevertheless, the winter and annual glacier mass balance show positive trends over 1961-2000 followed by a remarkable decrease in both summer and winter balances in the years 2000-2010 resulting in an average annual mass balance of close to -1 m w.e. (water equivalent) a-1 for the first decade of the 21st century. The mass balance sensitivities to temperature and precipitation variations are much larger for glaciers in maritime than for continental climate conditions. Despite the large extent of the Norwegian mainland from north to south, the mass balance sensitivities to temperature and precipitation changes show a stronger gradient from west to east. For the period 1961-2012, discharge is modeled for three catchments with a glacierization between 50-70 % situated along a west-east profile in southern Norway. The model simulations reveal an increase of the relative contribution from glacier melt to discharge from less than 10 % in the early 1990s to 15-30 % in the late 2000s. The decline in precipitation by 10-20 % in the same period was therefore overcompensated by increased glacier melt resulting in an increase of the annual discharge by 5-20 %. Discharge from the westernmost glacier catchment is most sensitive to changes in precipitation. In contrast, discharge from the easternmost catchment is most sensitive to changes in summer temperatures where glacier melt has become a large contributor to discharge during summer. Especially for more continental glaciers in Norway, this may lead to reduced summer discharge when their glacier area continues to decrease. For the three studied catchments, the increasing continentality from west to east yields larger differences in glacier mass balance, specific discharge and sensitivities to changes in temperature or precipitation than differences in catchment size or glacier coverage. However, plateau glaciers may have the largest potential to discharge changes in the future, when ongoing temperature rise continues. Furthermore, an assessment of meltwater contribution to discharge is performed for a catchment area in northern India. For this purpose, the glacier mass-balance model is implemented in a large-scale hydrological model that simulates discharge. The catchment area has a size of 5406 km2 of which 14 % is permanently covered with snow or ice. During the period 1997-2001, the contribution of glacier- and snowmelt in this catchment was accounting on average for 41 % of the annual discharge. The model results are an analysis of variations in the past, but can also serve to discuss changes in the present and prospective evolutions of glaciers and their impact on discharge from glacierized catchments in connection to further climate changes.