Stream temperature is controlled by local environmental and hydrometeorological conditions, and stream temperatures are known to respond to changes in the surrounding environment. Northern catchments with extensive permafrost have distinct hydrological processes, and are rapidly responding to climate warming, yet there has been limited research investigating stream energy balance processes under these governing conditions and their potential response to climate change. To address this shortcoming, this study establishes (1) the summer energy balances of four sub-Arctic headwater streams and (2) quantifies the potential stream temperature response to hydrometeorological and landscape changes, driven by climate change, expected to impact the study streams. The four study reaches were established in headwater catchments ranging in area from 5.4 to 15.2 km2, across a latitudinal gradient from 60.5 to 65.3ºN, and with catchment permafrost coverage ranging from 43 to 94%. Continuous hydrometric and meteorological observations at each study site through the open water period from 2022 through 2024 provide the basis for calculating the heat fluxes between the stream, the streambed, and the surrounding environment using the HydroCouple stream energy balance model. Results indicate offsetting temperature responses from increased groundwater and hyporheic exchange flows and increasing lateral inflow temperatures, with temperature responses ranging from +1.0 to -0.49ºC. The temperature response to riparian shrubification was greatest for the initial stages of shrubification, with rapid cooling of up to 1.2ºC. This study advances our understanding of stream heat exchange processes in northern environments and how they may respond to shifting environmental conditions in the coming decades.