This handbook provides guidelines for local governments in the Baltic Sea Region (BSR) to support them in preparing and drafting their climate change adaptation plans. These guidelines were elaborated by the Council of the Baltic Sea States Secretariat (CBSS) as a result of the project CliMaLoc – Climate Mainstreaming Locally in the BSR. The project – co-financed by the Swedish Institute – aimed to support local authorities in the BSR countries to mainstream climate and establish partnerships for cooperation in the future. This includes integrating climate aspects into local development plans, better aligning to the 2030 Agenda and supporting the efforts of the EU Strategy for the Baltic Sea Region (EUSBSR) (European Commission, 2021a) to promote low-carbon economies across sectors and policies. The CliMaLoc partnership engaged umbrella organisations for municipalities and regions in the BSR and implemented the project from June 2021 to March 2023.