“Corn Sweat” Compounds Humidity in Sweltering Midwest States

A cornfield in Dubuque, Iowa. Joshua Lott/Reuters

by Julia Fine, ODP Contributing Writer

This past weekend’s weather was hot in Iowa and Illinois. But it likely felt even hotter, due to “another episode of corn-catalyzed extreme humidity,” Matthew Cappucci reported in The Washington Post. “Corn sweat,” or the water released into the atmosphere by crops like corn as a cooling mechanism, helped make parts of Iowa and Illinois feel well over 100 degrees this weekend. 

Why This Matters: Corn sweat is no joke. As Cappucci noted, “the corn’s added moisture is working in tandem with longer-term human-caused climate change to bring increasing nighttime temperatures and humidity levels to the Corn Belt.” With high average nighttime temperatures and high humidity caused, in part, by corn sweat as well as human-induced climate change, means that there will be more frequent and more dangerous heatwaves. 

Changes to Corn Planting: The feeling of humidity caused by corn sweat may have been increased by changing planting practices. As Dr. Victor Gensini, a meteorologist, argues, farmers are planting rows closer together, which allows for more corn per a given unit of area. “That’s allowing more transpiration,” Gensini told WQAD. As the news outlet reported, on one particular farm in Illinois, they planted 27,000 crops per acre 30 years ago. Today, it’s almost 35,000. 

Impact of Corn Sweat: Even just one field of corn can raise the dew point, or the amount of water in the air, by 5 degrees Fahrenheit. According to David Montgomery in Bloomberg CityLab, a single acre of corn can “give off up to 4,000 gallons of water per day.” Because the US has more than 90 million acres of cornfields, corn sweat has an intense impact. 

Coupled with climate change, this corn sweat can have extremely dangerous effects. As Cappucci notes, “the synergy between elevated temperatures and humidity can dramatically exacerbate the risk for heatstroke and other heat-related illness.” In addition to being potentially harmful to the human body, increased humidity caused by corn sweat as well as high nighttime temperatures could be potentially harmful for crops as well. As the 2018 National Climate Assessment noted, these conditions could increase the number of “many agricultural pests and pathogens for both growing plants and stored grain,” which “likely will degrade market quality as well as yield by mid-century.” 


Up Next

Warming Temperatures Could Devastate Farms in East and Southern Africa

Warming Temperatures Could Devastate Farms in East and Southern Africa

By Ashira Morris, ODP Staff Writer If climate change keeps temperatures rising, staple crops in eight East and Southern African countries could decrease by up to 80% by midcentury. According to a new report by the UN’s International Fund for Agricultural Development (IFAD), a 2-degree Celsius increase in temperature (which the world is currently on […]

Continue Reading 417 words
Panelists Discuss More Sustainable Ways to Farm at Climate Week NYC

Panelists Discuss More Sustainable Ways to Farm at Climate Week NYC

By Natasha Lasky, ODP Staff Writer With drought continuing in the West, and the summer’s historic floods throughout Europe, the world is wondering how climate change will also affect the way we eat. This controversial question was addressed by agriculture experts, NGOs, government officials, and corporate leaders at Peas, Trees, and 1.5 Degrees, a Climate […]

Continue Reading 427 words
Food is the Future

Food is the Future

By Ashira Morris, ODP Staff Writer In the lead-up to today’s United Nations Food Systems Summit, young activists spoke about their priorities for the global gathering at yesterday’s Food is the Future event. At the event, youth representatives from worldwide  interviewed  adult peers in the world of food system work.    In an effort to […]

Continue Reading 380 words

Want the planet in your inbox?

Subscribe to the email that top lawmakers, renowned scientists, and thousands of concerned citizens turn to each morning for the latest environmental news and analysis.