Some scientists blame recent high humidity in Kentucky on ‘corn sweat’

A 2020 study showed that cropland, including corn, can increase moisture levels in the air by up to 40%.

Even in the dying days of summer, many Kentuckians are facing high humidity and heat indexes. Some scientists say corn crops could be partially to blame.

An environmental phenomenon known as “corn sweat” has gained traction on the internet. It’s the silly name for the biological process known as evapotranspiration, which occurs when corn plants pull water from the soil to cool down and release it back into the air as vapor. This process, when carried out by acres of corn crops, has been shown to increase a region’s humidity.

corn crop
A cornfield on Casky Lane at Bradshaw Road south of Hopkinsville. (Photo by Jennifer P. Brown)

2020 study from the Harvard-Smithsonian Center for Astrophysics analyzed data from past heat waves and found that cropland, including corn, can increase moisture levels in the air by up to 40%.

Shane Hollinde, the Outreach Manager for the Kentucky Climate Center, said the humidity comes from neighboring states, like Illinois, who start their corn season later in the year compared to Kentucky.

“You’re seeing more corn sweat in that part of the world because the corn there is still greener. It’s in mature form, whereas the corn here in Kentucky has already gone through its cycle of growth and maturity,” Hollinde said.

The state of Illinois has about 12 million acres of corn crops, Hollinde said, and each acre is capable of releasing around 4,000 gallons of water a day. According to Hollinde, the process could put as much as 48 billion gallons of water – the equivalent of a little more than 72,000 Olympic pools – into the air over Illinois each day.

Hollinde said that Kentucky may face temperatures of 90 degrees through September and into early October. He also said that Kentucky could see a decrease of corn sweat in the future as urban development takes up rural farmland.

This story is republished with permission from WKMS. Read the original.

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Zoe Lewis is a first-year sophomore at Murray State University from Benton, Kentucky. She is majoring in journalism with a minor in media production. She enjoys reading, going to movie theaters, spending time with her family and friends, and eating good food. Zoe is an Alpha Omicron Pi sorority member in the Delta Omega chapter. She is very excited to start working at WKMS and work while learning more about NPR, reporting, journalism, and broadcasting.