Climate change-related risks encompass an intensification of extreme weather events, such as fluvial and pluvial flooding, droughts, storms, and heat stress. A transparent and comprehensive division of responsibilities is a necessary—but not the only—precondition for being prepared for climate change. In this paper, we present, and preliminarily test, a method for the ex-ante assessment of the division of public and private responsibilities for climate adaptation in terms of comprehensiveness, transparency, legitimacy, and effectiveness. This method proofs particularly suited for the assessment of adaptation responsibilities in combination with a sectoral approach. It helps identifying a number of shortcomings in divisions of responsibilities for climate adaptation. We conclude that this method is useful as a diagnostic tool for identifying the expected climate change preparedness level, and recommend to combine this with ex-post analyses of real-life cases of extreme events in order to assess the actual preparedness for climate change. Besides the scientific purpose of providing a generally applicable assessment method, with this method, we also intend to assist policymakers in developing and implementing adaptation plans at various levels.