Pond‐breeding amphibians experience climatic variability primarily in the form of seasonal temperature fluctuations and water availability, two factors that are strongly influenced by shifts in climate. Larval amphibians are concurrently exposed to biological stressors, such as competition and predation, as they often co‐occur in diverse, multi‐species assemblages. Thus, to accurately predict species’ response to climate change, we empirically tested the interaction between a biotic and abiotic driver. We focused on three amphibian species that overlap in distribution and phenology across high elevations of the Cascade Mountain Range of the U.S. Pacific Northwest: the Pacific chorus frog (Pseudacris regilla), Cascades frog (Rana cascadae), and Western toad (Anaxyrus boreas). Amphibians in this region are threatened by drought‐induced habitat loss resulting from the shortened hydroperiod and, in some areas, complete elimination of seasonal wetlands. We conducted a fully factorial experiment to determine the interactive effects of competition and drying on amphibian growth, development, and survival. We found that the impact of drying on each species was largely dependent upon interspecific competition dynamics. Competitive interactions, particularly in the three‐species competition treatment, exacerbated the effects of drying, with both competition‐ and context‐dependent responses to these stressors. Through an analysis of species‐level effects, as well as an examination of secondary productivity (i.e., total biomass across treatments), we determined that Cascades frogs are the dominant competitor in this system owing to their larger body size and relative ability to withstand the stress of a rapidly drying hydroperiod. Our results suggest that ignoring biotic interactions in predictions of species response to climate change factors may be misleading.