PURPOSE: Many factors influence the occurrence and severity of geriatric trauma, and regional weather is regarded as one factor that influences geriatric trauma. In this study, to predict the type, severity, and incidence of geriatric trauma patient, we analyzed the influence of regional weather on geriatric trauma. METHODS: The subjects of our investigation were trauma patients over sixty-five years of age who visited the Emergency Department (ED) of Yeungnam University Hospital during a one-year period. We retrospectively reviewed the medical charts of 436 geriatric trauma patients, and the data were analyzed by using SPSS 12.0 for Window. The weather was based on data from the Korea Meteorological Administration. RESULTS: The average age was 72.8 years old, and the ratio of males to females was 1:1.1. The mean spell out ISS was 10.8, and no difference was found between males and females. Slips were the most common cause of trauma. The largest numbers of aged trauma patients, 46, visited the ED in May, and the smallest number of such patients, 24, visited the ED in December. In addition to, summer saw the largest number of aged trauma patients. The type of trauma, the Injury Severity Score, and the number of patients had no relationship with season. On sunny days, the ISS was larger in patients who had hypotension and who had tachycardia. On rainy day, the ISS was larger in male patients and cultivator accident patients. The number of patients was larger on partly cloudy days. CONCLUSION: In spring and summer and on partly cloudy days, we must be prepared to treat aged traumatized patients in the E.D. On rainy days, visual sensation, tactual sense, and acoustic sense must be closely examined. In addition,on rainy day, aged male traumatized patients or cultivator accident patients must to be closely observation.