There is a growing understanding that climate policy development has to rely on combined decentralized efforts and therefore has to take place at multiple levels and places including the local level. The hope of many emerging governance efforts such as municipal and city networks is that policies will then spread further and diffuse. Thus, policy diffusion has become a major governance approach in local climate policy. However, whether and how climate policy diffusion works remains severely underexplored. The present paper addresses this gap by studying the spread of adaptation policies at the local level, an integral part of climate policy where top-down governance is scarce and policy needs and effects are highly localized. Drawing on original representative survey data from municipalities in the State of Hessen in Germany (N=217), we test among several interest-, rights-, ideology-, and recognition-driven diffusion mechanisms (linked with the better-known mechanisms of coercion, learning, competition, and emulation) and their potential contribution to spreading local climate change adaptation policy. Our analysis relies on spatial regression models and connectivity matrices informed by multiple diffusion mechanism. We also study whether these mechanisms are conditional on socio-economic characteristics such as the size of municipalities. The results advance our understanding of policy diffusion by showing the (relative) contribution of different diffusion mechanisms for spreading adaptation policies. They are also important for policy-makers wishing to bank on policy diffusion to advance local resilience to climate change impacts.