Abstract The silking stage is an important event in the growth and development of the corn plant. Weather conditions at this stage can be critical to the final grain yield of the crop. Knowledge of the time of occurrence of the silking stage, as well as the weather conditions at that time, is important to individuals concerned with monitoring grain yield. Field observations provide estimates of crop development within the United States; however, these data are not readily available for other areas. A satellite-based method of monitoring the silking stage was developed and compared to ground-based estimates of the occurrence of the silking stage. Several vegetation indices, computed from weekly composites of visible and near-IR data of the NOAA AVHRR, estimated the occurrence of silking over large areas within 1 week of ground-based estimates. These indices may be the preferred method of estimating the occurrence of silking over large areas known to be predominantly planted with corn when reliable or representative ground-based estimates are unavailable.