Sweating Out a Record: AiQ Pegs U.S. Corn Yields at 184.7

AiQ pegs the national corn yield at 184.7 — A record crop, but what’s the delta? Together, the precipitation and temperatures imply yields on the top end of the range, 186.6. More nuanced data indicate a higher risk this summer, attributed to the magnitude of the overnight temperature rise. I was not very familiar with this phenomenon until a few weeks ago. Let’s explore the data in specific states facing the strongest anomalies.

Ag Experts: Can’t you just guess like everyone else?

AiQ: No.

If You Were Not Familiar with “Corn Sweat,” Join the Club

Corn Sweat is a new phrase; here is how you know. There are 5 years of Google search trends, where Uganda ranks second. The term likely gained traction due to its recent viral popularity, as evident in the post below.

When Barstool talks about Corn Sweat, it becomes a viral phenomenon.

People say it feels hotter—because it does. And if we can feel it, so can the crop. Let’s call it what it is: a response to high overnight temps—or not able to cool in the evenings—and elevated moisture. The issue isn’t what it’s called—it’s whether it matters.

We’ll address the real mechanism at play—evapotranspiration and potential water deficits—in our coming breakdown. For now, assume the effect is real; call it Corn Sweat, humidity stress, or hot nighttime temperatures. We don’t care. What matters is how it shows up in the data.

AiQ Yield & High Level Comments

Through late July, weather across most U.S. growing regions has been objectively favorable. Over 90% of normal precipitation has been recorded in major producing states, with the Northern Corn Belt leading the aggregate and the Eastern states benefiting from a wet spring that carried into summer—especially relative to the same period last year. Here are the % of normal precipitation since mid-June (versus 2024).

Illinois 95% (97%)

Indiana 97% (87%)

Minnesota 129% (126%)

North Dakota 126% (116%)

Kansas 102% (110%)

Ohio 101% (66%)

Pennsylvania 109% (76%)

AiQ’s national corn yield forecast stands at 184.7 bpa, with a range of 182 to 186.6 depending on late-season conditions. Barring any unexpected change, 2025 should set a new national record, but let’s first flag the “Corn Sweat.”

The 800-lb Gorilla: Humidity and Overnight Temps
Despite the mild aggregate temperatures, one anomaly demands attention: persistent high humidity and its effect on overnight temperatures. Known as “corn sweat,” evapotranspiration is the simultaneous loss of soil water and crop water through evaporation and transpiration. While a typical 200-bushel plant requires 20 inches of water, this year may necessitate more for normal development. This moisture traps heat, potentially disrupting the plant’s nighttime respiration and pollination processes—a subtle variable that models will struggle with.

AiQ’s data has flagged several states for analogs that have not been stellar years. Missouri, Illinois, Pennsylvania, Indiana, and Iowa are all experiencing hot relative nighttime temps, and in some cases, setting records. Temp anomalies have been hotter across the board in the Eastern Corn Belt.

The Illinois-Iowa Factor
Record national yields usually require stellar performance from core producers like Illinois and Iowa. While Illinois’ weather last year was textbook average—minimal anomalies across the variables we track—2025 has been good except for the overnight temps. AiQ indicates that Illinois yields could be down 7 bu/ac and Iowa 2.

Comparing this phenomenon to previous years is not apples to apples since most years with a similar profile were significantly wetter: 2021, 2019, 2018, 2015, 2011, 2010. Of the six highlighted, half underperformed the Illinois trend by a net average of 1 bu/ac.

The key question becomes: Can the U.S. set a national record without new all-time highs in Illinois or Iowa? Yes, but their margin for error will fall quickly. The foundation for a record crop is laid, but the final outcome depends on how these anomalies unfold during the remainder of grain fill.

Let’s Dive Into It.