The procedure for obtaining SCSI is extcolor{magenta}{summerized} in Algorithm 1. The connections between the rainfall anomaly in each region extcolor{magenta}{of Thailand} and SCSI are significantly negatively correlated. That means when the SCSI is higher(lower)-than-average, the rainfall anomaly is lower(higher)-than-average. During the monsoon season (JJAS), all SCSI are negative, with extcolor{magenta}{mostly observed} higher-than-average rainfall for each region, except for certain months, mostly less than 11.20% in each region, except the southern region, which is randomly distributed. This randomness makes it difficult to clearly specify the number of months that this assumption does not satisfy.