Some information states that the world is currently experiencing climate change. Many scientists have researched the relationship between climate change and various natural events. Still, there has been no research on the relationship between climate change and extreme rainfall events. The relationship between climate change and extreme rainfall events needs to be clearly understood, as extreme wet events can cause losses such as landslides in hilly areas, submerged agricultural areas, and damaged residential facilities due to flooding. Meanwhile, extreme dry events can lead to droughts and forest fires. The authors have proposed a procedure to utilize the upper and lower threshold values to determine the extreme rainfall. The proposed procedure uses correlation coefficient and regression modeling. The authors hope that engineers can estimate the extreme rainfall after understanding the relationship between climate change variables and the El-Nino Southern Oscillation (ENSO) on local rainfall. This study applied monthly rainfall data from the Alas Rainfall Station in Indonesia, climate change data, and ENSO from 1992 to 2021 to demonstrate the proposed procedure. The results showed that climate change affects the occurrence of Extreme Rainfall at the Alas Rainfall Station. The predicted extreme wet was 118.11%, and the predicted extreme dry was 72.12%. Extreme wet events are becoming more frequent, while extreme dry events are decreasing. The ENSO has no significant relationship to the extreme rainfall at several stations.