Thursday, Jul 2, 2026
Can ‘corn sweat’ worsen heat waves?
Water evaporating off of corn, known as “corn sweat,” can exacerbate heat waves by adding moisture to the air.
Known as “evapotranspiration,” the phenomenon occurs when water transfers from the corn’s surface or the soil to the atmosphere. This can result in higher dew points and humidity.
The crop can add as much as 4,000 gallons of water vapor to the air per acre each day. A study on a Midwestern heat wave in 2011 found moisture levels from crops rose by 40% over agricultural areas during daytime.
High dew points and humidity are common weather conditions each summer in Upper Midwest states, home to vast croplands. Minnesota is top five out of all states in corn and soybean production, giving it abundant sources of crop “sweat.”
This fact brief is responsive to conversations such as this one.
Sources
- The Ohio State University Extension Corn Sweat and Humidity: A Few Facts Explained
- University of Illinois Extension How does corn affect Midwest weather?
- Journal of Geophysical Research: Atmospheres Quantifying the Impact of Excess Moisture From Transpiration From Crops
- Minnesota Department of Agriculture Minnesota Agricultural Profile
About fact briefs
Fact briefs are bite-sized, well-sourced explanations that offer clear "yes" or "no" answers to questions, confusions, and unsupported claims circulating online. They rely on publicly available data and documents, often from the original source. Fact briefs are written and published by newsrooms in the Gigafact network.
See all fact briefs
MinnPost is an independent, nonprofit newsroom that produces thoughtful, in-depth journalism about civic and cultural affairs impacting Minnesota. Through our reporting, we take readers beyond the headlines and deep into the issues that matter through our public-service journalism, empowering them to engage in the politics and policy-making shaping Minnesota’s future.
Learn MoreLatest Fact Briefs
Was a Minnesota city nicknamed the ‘Athens of the West’?
Monday, Jun 15, 2026