The thermal environment and thermal comfort of an outdoor space have large spatial and temporal variations. To provide an overall picture, outdoor thermal comfort (OTC) should be analyzed on a yearly basic with high temporal-spatial resolution. The difficulty of annual OTC evaluation lies in the huge computational cost of wind simulations. Therefore, our study proposed a method to accelerate wind simulations through the use of Fast Fluid Dynamics (FFD), Proper Orthogonal Decomposition (POD) and Reynolds Number Independence (Re-independence). A case study of an actual urban building complex was employed to validate our study by comparing the integrated index Universal Thermal Climate Index (UTCI) results by our method with those by fully-resolved simulations. The average difference of UTCI was just 0.06 ∘C, indicating that the accuracy of our method is guaranteed. Besides, it only took 8 hours to complete the OTC assessment of this site with an area of 125,600 m2. The framework proposed in this study can be used to reveal the complete picture of OTC with affordable computational cost and reasonable accuracy.