Climate sensitive urban planning and building design require detailed information on effects of a changing climate. To simulate thermal building performance appropriate data are required as “standardized weather files”. But as historic weather records cannot be used to model building performance for future climate, synthetic “future weather” data are necessary. Here we present the steps to derive such data for the urban development project “Seestadt Aspern” in Vienna. We start with regional climate simulations with 10x10 km grid spacing, where hourly data for years of current and future climate have been extracted for the Aspern area. Micro-scale simulations at 5m-resolution have been carried out to consider local influences on urban micro-climate, taking regional simulation results as framework condition. As micro-simulation results are delivered only for single days, transfer functions have been developed to generate synthetic weather records, turning hourly regional climate simulation results into local climate characteristics.