Green roofs are widely recognized as a viable solution in the context of water-sensitive urbanization, especially with respect to their effects on heat island mitigation and future-proof urban drainage [1, 2, 3, 4, 5]. In order to support their dissemination throughout different regions, comparisons of performance under varying climatic conditions can be very useful. Storm characteristics such as rainfall depth, intensity and duration can be expected to play an important role, as well as the temporal distribution of storm events relative to seasonal patterns of temperature, radiation and wind. This paper summarizes the first of several such data- and model-based comparisons between Germany and China planned in the Sino-German cooperative project “Smart Technologies for Sustainable Water Management in urban Catchments as Key Contribution to Sponge Cities” (KEYS).