Healthy Food Delivery : Tired of Summer Humidity? If You’re In the Midwest, Blame the Corn

Tuesday, July 28, 2026

Tired of Summer Humidity? If You’re In the Midwest, Blame the Corn

The Midwest is known for its charm, friendly neighbors, and rolling farmland. Unfortunately, it’s also known for brutal summer heat and humidity.

One contributor to the scorching weather you probably haven’t heard of is corn sweat. It’s a real process that can contribute slightly to Midwestern humidity each summer.

Learn what corn sweat is, how it affects humidity, and why weather patterns remain the biggest driver of muggy conditions.

What Is Corn Sweat?

Corn sweat is “the natural process by which plants, in this case corn, move water through the plant to its surface, which then allows this water to evaporate into the atmosphere,” according to Ohio State University’s College of Food, Agricultural, and Environmental Sciences.

Basically, when in extreme heat corn plants release water vapor into the air through tiny openings in their leaves. This creates even more moisture and humidity in the surrounding air, especially in large cornfields.

When and Where Is Corn Sweat Strongest?

Corn releases the most moisture during the peak of the growing season, which is typically around tasseling and flowering in mid to late summer. During that stage, plants require significant amounts of water to support the rapid growth and reproduction it experiences.

At the end of the season, water use declines. Other variables like dry soil, drought conditions, low soil moisture, or extreme heat reduce how much moisture plants release. This is because corn naturally conserves water during stressful growing conditions.

Corn sweat can increase humidity close to the ground, particularly during periods when corn grows rapidly and has access to plenty of soil moisture.

The Midwest’s humidity is a result of several factors. Warm temperatures increase the atmosphere’s ability to hold moisture, while prevailing winds frequently transport humid air inland from the Gulf of Mexico. Lakes, rivers, forests, and crops like corn, contribute small amounts of moisture to those other conditions.

While corn sweat is real, it’s those other variables that are a much bigger factor.

“With all this information in mind, it is very unlikely that ‘corn sweat’ is contributing in any meaningful way to the recent stretch of muggy days,” according to Ohio State. “Instead, the current humidity is driven by more significant climate patterns such as large-scale atmospheric flows and its moisture advections (e.g. regional wind patterns).”