It’s been hot and humid lately. How hot and humid has it been? It’s been so hot and humid, even the corn is sweating.
Quoting an unimpeachable source I have discovered (more on this later), “corn sweat isn’t just a catchy term, it’s a very real meteorological phenomenon that significantly contributes to high humidity, oppressive heat index and the frequency of summertime thunderstorms across Iowa”. Who knew? Apparently not the experts at Iowa State University who don’t think it’s much of a factor.
Recently, a curious reader of the Cedar Rapids Gazette asked if Iowa’s corn does sweat and if so, does it affect our weather. The Gazette’s “Curious Iowa” series posed the question to the scientists at Iowa’s Department of Agriculture in Ames who reported that corn sweat, known in more scholarly and polite circles as “evapotranspiration”, refers to the process by which plants draw moisture from the soil and release it through their tiny pores into the atmosphere. It’s a real thing but—and our State Climatologist Justin Glisan concurs—it’s not a big thing.
According to Glisan, Iowa’s summertime weather is much more influenced by evaporation in the Gulf of Mexico. “Overall,” he told The Gazette, corn sweat “doesn’t contribute a significant amount” to Iowa’s weather.
On the other hand, ChatGPT, or Artificial Intelligence—which, I shouldn’t have to remind anyone– has the word “intelligence” right in its name, and rarely makes things up for no reason, states that corn sweat certainly does affect Iowa’s weather as well as our overall comfort. There is a good reason why Iowans feel hot and sticky and can hardly get our breath in the summer while people in New Mexico, for example, just feel hot. AI points out that a single acre of corn can produce 4,000 gallons of sweat every day. Then consider that Iowa raises some 13.1 million acres of corn. That adds up to 52 billion, 400 million gallons of corn sweat every single day! (And what a blessing that corn sweat smells nice!)
The former Speaker of the House of Representatives, Thomas “Tip” O’Neill once observed that “all politics is local”. The same might be said of weather. Iowa’s corn sweat raises our humidity but it doesn’t affect anybody in Death Valley or Hollywood.
To illustrate its point that corn sweat increases local humidity, AI cites the Iowa towns of Maurice, population 272 and home of the “Famous Maurice Fire Escape Slide” and Clarion, population 2,745 which happens to be the birthplace of the 4-leaf clover emblem adopted by 4-H Clubs of America. Both towns are right in the middle of corn fields and in July 2021, they both proved to be examples of corn sweat microclimates, registering very high humidity with heat indexes up to 130 degrees!
In addition to exceptional heat and humidity, AI claims corn sweat can contribute to spontaneous, local “pop-up” storms and is responsible for what is called “The Corn Belt Climate Feedback Loop” in which corn sweat leads to more rain which in turn makes the corn sweat more and so on. So far, there are no scientific studies indicating how many gallons of sweat Iowans produce. But if we sweated less, reducing the humidity, wouldn’t corn also sweat less and we’d have less rain and less corn? I guess we all have to do our part.