Changes in the intensity and frequency of hydroclimatic extremes can cause significant damage to social and economic systems. We investigate the projected changes in hydroclimatic extremes over the Great Lakes basin, a major freshwater supply in North America. We utilize five variables (maximum and minimum temperature, precipitation, and wind speed in north and east directions) from eight General Circulation Models (GCMs) of the latest Coupled Model Intercomparison Project phase 6 (CMIP6). We then apply the Multivariate Bias Correction algorithm (MBCn) to adjust for biases under two Shared Socioeconomic Pathways (SSPs) of SSP2-4.5 and SSP5-8.5. Climatic extremes are assessed using CLIMDEX indices for both historical and future warming levels of 1.5C � 4C above preindustrial levels. To investigate the hydrologic response of the Great Lakes basin, the state-of-the-art calibrated WRF-Hydro was forced by the bias-corrected climate variables. The changes in WRF-Hydro outputs, including streamflow and Snow Water Equivalent (SWE) under global warming temperatures compared to the preindustrial era, are investigated. Results show, under climate change, the Great Lakes basins, including Lake Erie, Lake Huron, Lake Michigan, Lake Ontario, and Lake Superior basins, and the St. Lawrence basin, will experience an increase in values of maximum one-day and five-day precipitation, and the number of consecutive dry days. Moreover, the number of consecutive wet days is increasing in all basins except the lake Michigan basin. Overall, our study highlights the potential impacts of hydroclimatic extremes on the Great Lakes basin and provides insights into the changes in hydrologic processes under climate change scenarios.