What is corn sweat? Heat wave in Midwest to feel worse this week, here's why
The Midwest is sweltering under humidity, and it turns out cornfields are a big reason behind it.
The hot and humid weather in parts of the central US seems to have turned unbearable lately, while corn is partly to blame for this. The term “corn sweat,” which refers to water transpiration from corn, has been floating around again as temperatures spike across the Midwest region. The weather phenomenon is tied to how corn plants release moisture.

What is corn sweat?
“Corn actually produces humidity, if you will, or moisture that wicks off the plant on average about 4,000 gallons per acre (per day),” farmer Mark Baker told AccuWeather.
The moisture adds to the already high humidity, pushing temperatures well over 100 degree Fahrenheit in parts of the Corn Belt like Iowa, Illinois, Missouri, and Indiana.
The effect isn’t subtle. “On a normal day, I mean, the humidity in the cornfield is substantially worse. You step out of the corn and you go, 'Wow, that's a breath of fresh air,” Baker added.
Does it have any effect on heat?
As per Accuweather, the whole thing boils down to plant biology - specifically, transpiration. Like all plants, corn pulls water up through its roots to grow. But the extra water does not stick around. Instead, the plant releases it through tiny pores in its leaves, sending vapor into the air.
A tree might do this too, but the numbers do not even come close. A big oak tree releases about 100 gallons of water a day. On the other hand, a single acre of corn releases up to 4,000 gallons. Multiply that by the roughly 11.1 million acres of corn in Illinois alone, and we are talking about billions of gallons of water vapor pumped into the air - every day - during peak summer season.
“Most plants do not transpire a significant amount of water. Corn plants are really, really effective at transpiration,” Illinois State Climatologist Trent Ford told Fox 32 Chicago.
Humid summers ahead
Chicago and much of the Midwest are now stuck in a steamy squeeze as they get caught between moisture-heavy Gulf air to the south and nonstop corn sweat rising from the ground. The result? Conditions feel way hotter than the thermometer suggests.
The upside? All that moisture means the corn is doing well, and farmers can expect a solid harvest come fall. So yeah, the sweat’s real - but at least someone’s thriving.
FAQs:
1. What is corn sweat?
Corn sweat refers to the moisture released by corn plants through a process called transpiration.
2. Why does corn increase humidity more than other plants?
Corn releases significantly more water vapor, up to 4,000 gallons per acre per day, compared to most plants.
3. Where is corn sweat most noticeable?
The effect is strongest in the Corn Belt states, especially Illinois, Iowa, Indiana, and Missouri.
4. Does corn sweat affect the heat index?
Yes, the added moisture raises humidity, which increases how hot it feels outside.
5. Is corn sweat a sign of healthy crops?
Yes, more transpiration generally means the corn is growing well and thriving.
ABOUT THE AUTHORHT US DeskThe Hindustan Times US Desk brings you the latest news and developments from across the United States. The team covers everything from breaking news and politics to sports, business, entertainment and stories that are trending across the country. Our coverage includes the White House, Congress, US elections, immigration and visa updates, H-1B, green cards, Social Security, education, jobs, layoffs, the economy, technology and major policy changes. We also closely follow stories that matter to Indian and South Asian communities in the US. The desk covers major US sports, including the NFL, NBA, MLB and NHL, along with player news, injuries, schedules, results and major events. Entertainment coverage includes Hollywood, celebrities, television, streaming, music and pop culture. We also report on breaking developments, major incidents, weather, public safety, court cases and other stories making headlines across the country. When a major policy or news development affects people's everyday lives, the team works to explain what happened, what it means and what readers need to know. Alongside breaking news, the US Desk produces explainers and practical stories on topics such as immigration, Social Security, taxes, education, employment and government programmes. The team also works on science, tech, business and AI stories analyzing the impact they may have on people. The team follows developments throughout the day, keeping an eye on official announcements, public records, reliable news sources and what people are talking about across the US.Read More

E-Paper


