The current landscape of climate services represents a highly diverse and still growing range of programs, projects, and portals involved in developing and/or providing climate services at different administrative levels and spatial-temporal scales. The diversity of service producers, users, and policy arenas has created a highly heterogeneous data- and information-oriented service landscape, and the authors contend that the domain of climate services requires efforts toward agreed structures and forms of conceptualization, operationalization, and evaluation. It is proposed here that qualitative classification be applied into climate change adaptation products, services, and systems to better guide research, policy, and practice with a clear terminology and analysis framework. This differentiation allows the pinpointing of critical challenges associated with the production and application of climate-relevant information, as well as the identification of suitable metrics to assess the impact of climate services. The article concludes with recommendations to advance climate services into knowledge-action systems and increase their sustainability.