Phenology - the timing of life events - determines how a species’ life cycle aligns with the abiotic and biotic environment, however, climate change has altered the environmental cues organisms use to track climate leading to shifts in phenology. In high latitude environments, phenological shifts in plants are associated with both temperature and the timing of snowmelt, but the mechanism underlying the effect of snowmelt on phenology remains unclear. Here we aim to disentangle the effects of experimental warming and earlier snowmelt on the phenology of three long lived perennial wildflowers. In the summer of 2019, we factorially crossed passive warming with early snowmelt timing within a subalpine plant community in the Colorado Rocky Mountains at the Rocky Mountain Biological Laboratory to understand the individual effects of these aspects of climate change.