During the first half of the twentieth century, climate data was rigorously collected throughout the Belgian Congo. Yet today this data is practically absent from (international) data repositories and not included in (re-analysis) climate models. The historical archives of La régie des plantations de la colonie (REPCO) and the Institut National d Etudes Agronomique du Congo Belge (INEAC) archives hold vast amounts of (eco-) climatological data, with great potential and relevance for basic and applied research in the central Congo Basin. They are currently stored at the State Archives of Belgium, the Royal Museum for Central Africa and the Botanic Garden Meise in Belgium. In 2017, the Congo basin eco-climatological data recovery and valorization (COBECORE) 4-year project was launched with the aim to valorize this legacy data by making it accessible for contemporary research through computer vision, machine learning and citizen science approaches. Here we report on the completion of scanning activities during the first year of data recovery for 575 climatological stations spread throughout the Congo Basin, equivalent to 4300 site-years (50 000 scans). We provide an overview of the climate stations where this data was collected during colonial times, as well as the parameters and timeframe for which we have data.