This study evaluated the differences in sorghum-sudangrass hybrid (SSH) forage production in Korea under extreme and normal climate conditions. Data for SSH (n=1,025) sources were analyzed from the Rural Development Administration’s adaptability reports on new varieties between 1979 and 2019. The climatic data, including mean and highest air temperatures, maximum hourly precipitation, accumulative precipitation, maximum and mean wind speeds, and sunshine duration, were derived from the Korean Meteorological Administration and were calculated for ten-day intervals during the SSH growth period. Box plots were used to detect outliers and distinguish extreme and normal climate conditions. The dry matter yield disparity under extreme and normal climate conditions was determined using a t-test at a 5% significance level. The study identified a considerable incidence of spring droughts accompanied by severe winds and a summer-to-autumn monsoon season with excessive rainfall under extreme climatic conditions. The estimated impact on SSH production (kg/ha) ranged from 1,961–6,541 in spring, 2,161–4,526 in summer, and 508–5,582 in autumn. The study establishes a foundation for assessing vulnerability and estimating damages associated with climatic variations in Korea, underscoring the importance of evaluating the impact of extreme weather events on forage production.