MK-PRISM developed for wind interpolation was applied to case studies and was verified in previous studies. Thus, some tests were necessary before the model used in order to produce wind speed maps for the whole area of South Korea. In this study, the MK-PRISM was applied to producing wind speed maps of South Korea. The result showed that sharp changes occur in wind speed distribution, despite the continuous similar topographic. The primary reason for the phenomenon was that a linear regression slope between elevation and wind speed used in interpolation process was changed rapidly in some areas. This study used the landform classification data to address this problem. The improved model controlled similarly the slope of the linear regression equation in the continuous valley, slope, and ridge. Therefore, the slope of the linear regression equation does not change dramatically in the improved model. The improved model was named MK-PRISM-Wind in this study. The wind speed was similar on the ridge continuously in the wind speed distribution produced by MK-PRISM-Wind. In addition, the wind speed was more gradually changed compared to the previous model on the plains and foothills. The results mean that MK-PRISM-Wind can produce wind speed maps more reasonable than the previous model, and it can be applied to the wind speed interpolation of South Korea. High-resolution gridded wind speed map produced by MK-PRISM-Wind is expected to be utilized for various studies.