A method of simulating individual cow milk yield per milking as a function of herd milk yield and month was formulated for milking parlor simulation models. Milk yield per milking was modeled for each month in three herd milk yield categories: 8165, 8845, and 9525 kg/yr of milk per cow. Actual individual cow DHIA test day milk weight data for three Florida dairy herds in each herd milk yield category and month were adjusted to the mean of their respective actual milk shipped per cow on test day then pooled and converted to a basis of three times per day milk yield per milking. After minor truncation, Weibull probability distributions fitted to these data sets adequately modeled milk yield per milking per cow. Analysis of simulation results for milk yield per milking per cow indicated no significant differences between actual and simulated means for any herd milk yield category or month. Simulations of monthly and yearly total herd milk yield for each herd indicated that fitted Weibull distributions also adequately modeled monthly and yearly herd milk yield characteristics and reflected seasonal herd milk yield patterns typical of Florida.