Climate adaptation is inevitable to managing the climate risk of infrastructure systems and has become an emerging topic in the past decade. Despite the growing need for collaborative and multi-agency efforts in climate change adaptation, however, current airport and transportation governance structures reinforce siloed approaches to manage climate risk. Here we combine a novel coastal flooding exposure assessment of California’s airports and a policy review to address the importance of collaborative climate adaptation by viewing airport infrastructures as interconnected systems across spatial scales and sectors. Our exposure assessment innovates by investigating the airport perimeter, its interconnected infrastructure (road access, ground-based navigation and communications systems), and multimodal interregional transportation corridors. At the local scale, we find that substantial airport assets are exposed as early as 2020–2040, suggesting the urgency for near-term adaptation actions. Regarding the interconnected infrastructures, 23 unaccounted airports are identified at risk of disruption when compared with existing studies, including global hubs such as the Los Angeles International Airport. At the regional scale, we investigate how exposed airports transfer risk within the interregional multimodal transportation corridors, and we identify the critical airports within these corridors to be prioritized for adaptation. Finally, based on a policy review of more than 100 state legislature and planning documents, implications of our results are discussed at the national and state levels. This study presents a new generation of infrastructure exposure assessment to climate-induced hazards, by addressing cross-sectoral and multiscalar dependencies that are currently overlooked by adaptation policies. We also argue that new modes of collaborative efforts are needed to achieve effective climate adaptation for interconnected infrastructures.