The concept of smart cities is often associated with technological advancement, but it also encompasses aspects of citizen well-being and sustainability. The growing availability of digital data results in an excessive focus on technology, neglecting citizen participation and consequently underutilizing the potential of this information. Our hypothesis is that design can facilitate access to complex urban data through data storytelling and participatory processes. Therefore, we tested a co-design process using mixed methods to analyze mobility behavior. Structured in two phases, the study initially explored mobility projects by analyzing reports from the Civitas initiative and interviewing professionals in the field. The identified challenges and solutions were then tested in the second phase, employing data collection methods such as city open data analysis, diary studies, and sentiment analysis on social media. Finally, a co-design workshop was conducted incorporating data visualization tools to co-analyze the weather effects on urban mobility. The results highlight the significant potential of the designer as a facilitator, with participants reporting ease in analyzing substantial data volumes and considering the proposal innovative and enjoyable. Future research may evaluate participants understanding of the data. The contribution of this thesis lies in a co-design process that can involve various stakeholders, including government, private enterprises, and citizens, using data storytelling tools applicable to any project dealing with large data volumes.