A risk information processing method is used in a risk information processing system that manages a degree of risk at a target spot at which a moving object is located. The method includes: receiving sensor data collected at each of two spots different from the target spot; determining a degree of risk of an event at each of the two spots from the sensor data collected at each of the two spots; storing, as risk information the determined degree of risk associated with each of the two spots; estimating first risk information associated with the target spot without sensor data of first event at the target spot, by using the stored risk information, the first risk information being a degree of risk of the first event at the target spot; and outputting information for the target spot based on the estimated first risk information.