The development and dissemination of weather and climate information is crucial to improve people's resilience and adaptability to climate variability and change. The impacts of climate variability and change are generally stronger for disadvantaged population groups due to their limited adaptive and coping capacities. For instance, smallholder farmers living in remote areas such as the southern Peruvian Andes suffer strongly from adverse weather and climatic events such as droughts or frost. The project Climandes aimed at providing high-quality climate services in support of the agricultural sector in southern Peru by implementing the guidelines of the Global Framework for Climate Services (GFCS). In Climandes, a two-fold challenge was tackled: the co-development of climate services by building up a continuous dialogue between the information provider (in this case the Peruvian national meteorological and hydrological service (NMHS)) and potential users; and the production of climate services through international cooperation. To this end, the NMHSs of Peru (SENAMHI) and Switzerland (MeteoSwiss) worked closely together to tackle issues ranging from the treatment of climate data to ensure the provision of reliable information to establishing continuous interaction with different user groups. In this paper, we postulate that this approach of close collaboration, the so-called twinning of the two NMHSs, was key for the projects’ success and contributed to strengthening the Peruvian NMHS institutionally and procedurally. This project overview guides its reader through the approach, main achievements, and conclusions regarding successes and challenges of the project, and reflects on some potential improvements for future initiatives.