Significance Climate warming is impacting the cryosphere in high mountain ranges, thereby enhancing the probability for more and larger mass-wasting processes to occur. This tree-ring–based snow avalanche reconstruction in the Indian Himalayas shows an increase in avalanche occurrence and runout distances in recent decades. Statistical modeling suggests that this increase in avalanche activity is linked to contemporaneous climate warming. These findings contradict the intuitive assumption that warming results in less snow, and thus fewer snow avalanches in the region, with major implications for disaster risk management and risk mitigation in a region with steadily increasing human occupation.