Corn is generally grown in areas that receive more than 25 inches of rain annually, with between 18-20 inches falling during the growing season, which runs from May to October. In the regions that usually record less rainfall, fields are irrigated to produce high yields.
As a corn plant grows, the demand for water increases as more leaves sprouts on the stalk. Dry silks can limit the corn plants' ability to transfer pollen, and adequate moisture is also necessary as the kernel develops.
Pre-growing season (October - April) rainfall is essential for recharging soil moisture between each season.