Because of their unique physiology, lichen communities are highly sensitive to climatic conditions, making them ideal bioindicators for climate change. Southeast and south-central Alaska host diverse and abundant lichen communities and are faced with a more rapidly changing climate than many more southerly latitudes. We develop sensitive lichen-based indicators for tracking the effects of climate change in south-central and southeast Alaska. Using 196 plots, we model community composition and 12 individual species abundances in relation to synthetic climate variables. Both types of lichen indicator are closely related to the climate variable describing a transition from warm, wet oceanic climates to cooler, drier suboceanic climates. Lichen communities and individual species exhibited thresholds associated with average December minimum temperatures between −10.2 and −7.8°C and annual precipitation between 106 and 172 cm, suggesting rapid turnover with relatively small changes within these ranges. These climate conditions occur close to the coast in northern portions of the region and further inland in southeast Alaska. Because lichen communities in the threshold region may be most sensitive to a changing future climate, they should be targeted for monitoring efforts.