"Corn sweat" is a colloquial term used to describe the natural process called evapotranspiration, where corn plants (and other plants) move water from the soil through their roots and leaves and release it into the air as water vapor. This process helps the plants cool off but also increases humidity in the surrounding atmosphere. One acre of corn can release about 3,000 to 5,000 gallons of water into the atmosphere per day during peak summer growth stages. This moisture release can make the local air feel more humid and sticky, especially during hot weather. The increased humidity from corn sweat can exacerbate the discomfort of heat waves by making the atmosphere feel hotter and more oppressive. Corn sweat is most noticeable during the peak summer months when corn is in its reproductive stage (pollination and grain fill), and the plant is actively transpiring water to cool off. While the added moisture from corn sweat is relatively small compared to the overall humidity driven by broader climate patterns, being near a cornfield during this time can make one feel the effect more acutely. In summary, "corn sweat" is essentially the water vapor that corn plants release into the air, contributing to increased humidity and sometimes making hot summer days feel even more uncomfortable in corn-growing regions like the U.S. Midwest. This phenomenon is an example of evapotranspiration, a natural and important agricultural process.
