Decadal prediction systems are designed to become a valuable tool for decision making in different sectors of economy, administration or politics. Progress in decadal predictions is also expected to improve our scientific understanding of the climate system. The German Federal Ministry for Education and Research (BMBF) therefore funds the German national research project MiKlip (Mittelfristige Klimaprognosen). A network of German research institutions contributes to the development of the system by conducting individual research projects. This special issue presents a collection of papers with results of the evaluation activities within the first phase of MiKlip. They document the improvements of the MiKlip decadal prediction system which were achieved during the first phase. Key aspects are the role of initialization strategies, model resolution or ensemble size. Additional topics are the evaluation of specific weather parameters in selected regions and the use of specific observational datasets for the evaluation.
