To assess the possible impacts of climate change and plan the necessary adaptation measures, countries need to analyze complex and multilayered information. Data often belongs to different disciplines and institutions and is hard to interpret for policy making in its raw form. Boundary organizations have a pivotal role in facilitating discussion between academic and political actors and producing tools to assist in decision-making processes. Hungary, an Eastern European country, faces climate change effects ranging from changes in precipitation patterns to increasing frequency of weather extremities. This article examines the establishment of a boundary organization, the National Adaptation Centre, and its decision support tool, which aims to assist the territorial planning of the country. Through this, we identify the extent to which the National Adaptation Geo-Information System (NAGiS) tool has had an impact on collaboration pattern designs and policy making. The study finds that NAGiS supports policy development at different levels of governance. At the same time, the introduction of this information and communication technology tool was not sufficient to create a breakthrough or counteract other factors such as the low salience of the issue at the national level. Furthermore, the introduction of NAGiS did not change formal structures or procedures. However, it did have an impact on attitudes toward data sharing, which in turn shaped collaborative practices. The organizations involved generally evaluated the effects of the tool on their collaboration as positive and lasting beyond the development phase of the project. Changed attitudes may prove important for enhanced internal collaborative governance down the line. András Molnár, Sara Svensson, Published by Common Ground Research Networks.