Changes in weather conditions impact construction activities. The consideration of effects of changes in weather condition is important to better estimate the performance of construction resources. This paper demonstrates the integration of a weather generator to support modelling earthmoving operation using distribution simulation with high level architectural (HLA) standards The modelled earthmoving operation is related to the oil sand mining. The weather effects on the breakdown and maintenance events of earthmoving resources (trucks and excavators) were analyzed under different weather testing scenarios and their results were reported accordingly.