Western coastal area of Chungnam, including Cheonsu Bay and Garorim Bay, has suffered from hot and coldextremes. In this study, the extreme sea surface temperature on the western coast of Chungnam was analyzed using thequantile regression method, which extracts the linear regression values in all quantiles. The regional MOHID (MOdeloHIDrodinâmico) model, with a high resolution on a 1/60ogrid, was constructed to reproduce the extreme sea surfacetemperature. For future prediction, the SSP5-8.5 scenario data of the CMIP6 model were used to simulate sea surfacetemperature variability. Results showed that the extreme sea surface temperature of Cheonsu Bay in August 2017 wassuccessfully simulated, and this extreme sea surface temperature had a significant negative correlation with the Pacificdecadal variability index. As a result of future climate prediction, it was found that an average of 2.9oC increased duringthe simulation period of 86 years in the Chungnam west coast and there was a seasonal difference (3.2oC in summer,2.4oC in winter). These seasonal differences indicate an increase in the annual temperature range, suggesting that extremeevents may occur more frequently in the future.