The overall goal of AQUACLEW was to use innovative research techniques and integrated co-development with users to advance the quality, and usability of climate services that provide climate change information to water related sectors. Data and information in present climate services reflect high uncertainties and low resolution, which is difficult to use in practical climate adaptation work. The works in AQUACLEW aimed at improving confidence and site-specific information by better tailoring climate data and adaptation knowledge. In AQUACLEW, we not only co-developed the climate services with users, we also co-developed the research requirements, the services’ interfaces and the guidance tools. By integrating users and researchers throughout the climate service production chain, the quality, usability and user uptake of climate services for water are improved. Data providers and researchers can more fully understand user’s needs and users were able to update on the latest scientific knowledge. With a better understanding of the potentials and limitations of the data, users can influence (choose between) assumptions made in each step when producing the services’ outputs. In AQUACLEW, we developed regional, national and pan-European climate services and indicators of climate change impacts together with about 30 users. Outputs were evaluated in 7 real-world climate adaptation case studies across Europe. These covered a diverse range of water-related sectors, i.e. (i) flash flood risks in pre-alpine regions, (ii) flash flood risk in urban areas, (iii) drought and water resources allocation for industry, tourism, agriculture and energy, (iv) hydropower production, (v) biodiversity, (vi) agricultural production and (vii) sediment transport and coastal erosion.