According to calculation steps as presented in Section 3.2, the wind speed data in Table3 were tabulated in SPSS. The agglom- eration schedule for the data was obtained. These data are pur- posely used to plot the scree diagram to determine the number of clusters in volved in the wind speed prediction analysis. By using a graph plotter function in Micros oft Excel, the scree diagram, with respect to the stage number is plotted in Fig. 6. The orange- coloured circle in Fig. 6 indicates the numbers of the stages that started to become a steeper graph because a larger number of cases are joined together into significant clusters. Therefore, the ideal number of clusters for the analysis is five. Thereare 96 cases in total. By subtracting 91 from the total cases, there are five clusters.