Local public health authorities often lack the capacity to adapt to climate change, despite being on the 'front lines' of climate impacts. Upper-level governments are well positioned to create an enabling environment for adaptation and build local public health authorities' capacity, yet adaptation literature has not specified how upper-level governments can build local-level adaptive capacity. In this paper we examine how federal and regional governments can contribute to enabling and supporting public health adaptation to climate change at the local level in federal systems. We outline the local level's self-assessed adaptive capacity for public health adaptation in Canadian and German comparative case studies, in terms of funding, knowledge and skills, organizations, and prioritization, drawing upon 30 semi-structured interviews. Based on interviewees' recommendations and complemented by scientific literature, we develop a set of practical measures that could enable or support local-level public health adaptation. We find that adaptive capacity varies widely between local public health authorities, but most report having insufficient funding and staff for adaptation activities. We propose 10 specific measures upper-level governments can take to build local public health authorities' capacity for adaptation, under the interrelated target areas of: building financial capital; developing and disseminating usable knowledge; collaborating and coordinating for shared knowledge; and claiming leadership. Federal and regional governments have an important role to play in enabling local-level public health adaptation, and have many instruments available to them to fulfill that role. Selecting and implementing measures to enable local public health authorities' adaptive capacity will require tailoring to, and consideration, of the local context and needs.