Supraglacial streams are a significant part of the glacial hydrological regime and important for understanding the dynamics between glacial hydrology, glacier dynamics, and climate change. During the 2014 ablation period on Bylot Island, Nunavut, a supraglacial stream, which flowed over a 13 m high waterfall at the front of Fountain Glacier, began to pulsate. The pulsating phenomenon involved the stoppage of flow over the waterfall for 10-15 s, with a total period of 27 s. The objective of this research was to determine the factors that influenced the evolution of the supraglacial stream. Results show a change in the weather, where multiple rainfall events occurred during the second week of the study. Analysis suggests that the rainfall caused the formation of a step-pool sequence within the streambed. In conclusion, the formation of the step-pool sequence and constructive interference from changes in flow conditions caused the distinctive pulsating.