Upwards of 95% of Yukon residents depend on groundwater for drinking water, including many First Nations and isolated communities. In subarctic regions, permafrost is widespread and interacts with groundwater. Potential warming-induced thaw will result in changing flow paths, solute release, and exposure of groundwater to different lithologies. Future projections suggest thicker active layers, enhanced drainage, and greater surface-groundwater interactions. In terms of solutes of concern, arsenic and uranium are toxic to humans and pose threats in groundwater around the world. In this study we seek to characterize the factors that contribute to arsenic and uranium concentrations in groundwater across Yukon and identify regions where groundwater security is at greatest risk presently and in a warming world. Groundwater geochemical, physical, and well log data was collected in 2021 and 2022 during the spring, summer, and fall seasons from 45 Yukon Government monitoring wells. In addition, further sampling was targeted at wells that are not monitored regularly and have past records of high arsenic and uranium. Results suggest considerable variation in groundwater geochemistry across Yukon, reflecting the territory�s complex geology. Principal component analysis suggests that several factors contribute to the variability in groundwater quality. Parent material is a primary influence on weathering solutes and base cations, and uranium concentrations are most closely related to it. Arsenic appears to be influenced by redox conditions as well as parent material. Ongoing work will relate spatial patterns to the permafrost probability and lithology, with the goal of informing risk management for Yukon drinking water.