As of Sunday, July 1, 16 percent of Iowa’s corn crop had silked, two weeks ahead of normal (USDA July 1). A good share of the crop will silk in the next few days to two weeks. This is the most critical time for corn in terms of effects on yield potential (see Elmore ICM News), a time when water use maximizes (seeAl-Kaisi et al., ICM News). Unfortunately, this timing coincides with dry soils across most of Iowa and a forecast for unseasonably high temperatures at least through the end of this week. Many wonder about the impact of this ‘perfect storm’ on corn yield potential. How will this rare combination of circumstances - corn at the most critical developmental stage, dry soils and hot dry weather persisting for several more days – impact yield potential? The corn simulation model, Hybrid-Maize, helps us address these questions.