We developed and evaluated the average skills of six deterministic ensemble methods using randomly generated data and the seasonal mean temperature and precipitation over South Korea simulated by five regional climate models (RCMs).The six ensemble methods are as follows: Equal weighted averaging without bias correction (EWA_NBC), equal weighted averaging with bias correction (EWA_WBC), weighted ensemble averaging based on the root mean square errors (RMSE) and correlation performance (WEA_RaC), weighted ensemble averaging based on Taylor score (WEA_Tay), weighted ensemble averaging based on trend skills (WEA_Trd), and multivariate linear regression (Mul_Reg).