The Pacific Northwest is experiencing a combination of warming average temperatures and more frequent extreme weather events. While wildlife climate studies generally focus on responses to increasing average temperatures, understanding the potential interactions between mean temperature shifts and extreme weather is paramount to predicting climate-induced ecological impacts. We empirically tested the hypothesis that organisms exhibit an additive response to combined temperature stressors using a fully factorial experimental design. Pacific treefrog (Pseudacris regilla) tadpoles were reared until metamorphosis under two mean temperature treatments (current climate, future climate) and two extreme weather event treatments (control, heat wave). The heat wave treatment mimicked aquatic conditions experienced during the 2021 heat dome in the Willamette Valley, Oregon. In addition to growth and development endpoints, we collected whole-body microbiome samples from each treatment group before and after the heat dome exposure. Here, we summarize the microbiome analyses. Bacterial community composition, alpha diversity, and beta diversity were compared between treatments using 16S rRNA amplicon sequencing and Bayesian Dirichlet-multinomial regression. We observed an interactive effect between climate and heat dome treatments on the relative abundances of bacterial taxa and alpha and beta diversity. Specifically, adding an extreme temperature pulse reduced microbiome diversity in the current climate treatment, whereas the pulse increased diversity in the future climate treatment. Further, a substantial amount of variation in community composition was driven by a single taxon with potential digestive function. Our findings emphasize the importance of understanding organismal responses to a combination of climate stressors to inform conservation and management priorities.