Weather-related risks can substantially affect the crop volume depending on time and intensity of agricultural operations performed by the farmer. However, decisions under uncertainty are in some way also liable to another risk – that of excessively optimistic or pessimistic estimation of the decision maker. The paper presents results of optimistic and pessimistic farmer’s agricultural operations efficiency based on the analysis of the developed discrete-event stochastic simulation model. The aim of the model is to obtain quantitative estimation of optimistic and pessimistic farmer’s choice of agricultural operation strategy efficiency under fluctuation of weather conditions.