We have investigated coarse wind sectors in Busan metropolitan area and simulated detailed wind field using local atmospheric circulation model, RAMS in preceding studies (Part I, Part II). In this study, we divided and analyzed local wind sector in Busan according to the preceding results. We found that Busan metropolitan area is divided into 2 or 3 local wind sector in each coarse wind sector. The 9 coarse wind sectors were classified into 20 local wind sectors in total. But three local wind sectors were finally excluded because of these sectors were located on the complex hill area and the sea. Local wind sectors, therefore, in Busan metropolitan area were defined as 17 regimes. We assessed the location of air qualify monitoring sites at Busan metropolitan area using the information of these wind sectors. Most of these were located at proper points, but 6 sites were placed at 3 local wind sectors as a couple and no site was set up at 3 other sectors. Hence the location of these sites was in need of rearrange.