Climate change and the Urban Heat Island (UHI) effect present significant challenges for compact cities, as the increasing frequency of extreme weather events heightens concerns about urban microclimates, emphasizing the need for improved microclimate research. Urban greenery is a critical strategy for mitigating UHI effects. Using a campus in Singapore as a testbed, this study proposes a method for integrating multiple data sources to develop a comprehensive, high-detail model of urban greenery. This model is incorporated into the unified 3D model and Geographic Information System, contributing to the development of a digital twin. The case study further investigates the microclimatic effects of greenery by comparing measured weather station data with digital twin simulations. The resulting detailed digital twin platform provides a robust foundation for further research on sustainable urban environments and can be adapted for diverse applications in environmental modelling and urban resilience studies.