This chapter explores the dynamic relationship between climate conditions and the risk of indoor overheating across Europe, with a specific focus on the distribution of hot days and tropical nights. It delves into how geographical factors such as latitude, proximity to the sea, and altitude influence local temperature and radiation conditions, shaping distinct microclimates that affect thermal comfort within buildings. Urban climatic features are discussed to underscore the complexities these environments present, particularly in terms of modifying local climates which exacerbate heat risks. The chapter further addresses the challenges in selecting appropriate climate datasets for overheating risk assessment. It illustrates these challenges through an analysis of weather dataset characteristics, highlighting the ambiguity in determining which dataset might be most critical for risk evaluation. The impact of using different climate datasets on the perceived overheating risk of a specific example building is also examined. Various reference datasets for building simulation were compared, along with different approaches to modelling urban climatic effects and implementing future climate scenarios. This analysis reveals significant variations in risk assessment outcomes depending on the chosen dataset, thereby emphasizing the need for careful selection and consideration of local climatic nuances in building design and urban planning to mitigate overheating risks effectively. This comprehensive approach not only helps in understanding the broader implications of climate change but also guides stakeholders in making informed decisions to enhance indoor environmental quality and occupant health.