The melt period in the Canadian Arctic is becoming prolonged as the climate warms. Consequently, understanding the water chemistry of what is discharged from these cold-region landscapes is becoming increasingly important. This study examines the seasonal and temporal shifts in stream water geochemistry of both glacial- and non-glacial-fed watersheds on Axel Heiberg Island, Nunavut. Over a two-month field season, the dominant water source of the streams transitioned from dilute snowmelt to more concentrated groundwater. Major ion chemistry revealed consistently acidic, sulfate-dominant waters. Early results from stable sulfur isotopes and scanning electron microscopy suggest that the surplus of sulfate originates from the weathering of shales within the watersheds. Geochemical modeling indicates that the waters acted as net carbon sources, contrasting with previous studies of carbonate-dominant glacial systems that acted as carbon sinks. Stable water isotopes (O and H) became increasingly enriched as the melt season progressed. Across all watersheds, these values plot close to the Local Meteoric Water Line, suggesting that the glacial component may be less hydraulically active than previously hypothesized. This research combines water quality data, isotopic tracers, and geochemical analysis to advance understanding of surface-groundwater interactions in High Arctic watersheds. The findings have implications for understanding downstream ecosystems and carbon fluxes as melt seasons continue to lengthen.