This study attempted to predict the yield of wheat cultivars differing in maturity and planting date, and resistance to stem rust in four seasons. The highest yield ranking was associated with the earliest planting date (October) with a yield improvement of 184.55% compared to the latest date (January). Planting wheat cultivars at the optimum date (November) increased the yield ranking by 153.09% compared to very late plantings. Early onset of stem rust in wheat cultivars planted at different dates increased the maximum disease severity by 62%. Early onset of the disease improved the yield ranking by 27% compared to late-onset. The first principal factor was defined as the progress of stem rust related to weather. The second principal factor defined stem rust, planting date, and yield. The third principal factor defined stem rust resistance. The fourth factor contributed to the exponential parameters b and r. The results of the factor analysis simplified the selection of predictors for the model according to predictive values of the crop, stem rust, and weather descriptors tested at the field plot scale during four seasons. The model explained 96% of the variations in wheat yield. The higher yield was associated with earlier planting date and stem rust onset, fewer rainy days in the spring months, warmer spring, and higher wheat resistance index when interacting with a greater area under the stem rust progress curve.