The relationship among rice yield and weather variables in Korea is explored using a stochastic production function. The results reveal that average rice yield is positively related to temperature and negatively associated with precipitation. Both temperature and precipitation, which are risk-increasing inputs, are positively related to rice yield variability. The widened yield variability can be transferred to the fluctuation of rice production and rice price instability. Larger market risk is expected in the future since both temperature and precipitation are anticipated to increase. An evaluation of climate change impact on rice yield variability reveals that it may increase by up to 10%~20%. Reducing yield variability and managing market risk would be the primary goals of the government's farm policy and research.