THE MUGGY MIDWEST: 

As temperatures soar across the Midwest, the regional phenomenon of “corn sweat” is making matters worse from a humidity perspective.  

The Midwest is already dominated by humid Gulf air, but with the addition of corn sweat, the dew point continues to climb past seasonal averages. The higher the dew point, the more moisture there is in the air. 

Once dew points surpass 75 degrees, it’s considered oppressive. Many locations across the Midwest are expected to see dew points reach as high as the mid-70s over the next few days.

WHAT IS CORN SWEAT: 

“Corn Sweat” is technically considered the process of evapotranspiration. That’s when plants absorb moisture through their root systems, use the water to create food for themselves, and then release water vapor once the process is complete. And corn can produce a lot of water vapor.  

According to NWS Sioux Falls, just one acre of corn releases 3,000 – 4,000 gallons of water each day. That means states like Illinois which have around 12 million acres of corn (which is about twice the area of New Jersey) can produce upwards of 48 billion gallons of water each day. That’s nearly 73,000 Olympic-sized swimming pools every day. 

Corn sweat isn’t a bad thing though. It can be a sign that crops are growing to their fullest potential, said Talon Becker, University of Illinois Extension commercial agriculture educator to agdaily.com.  

Despite the name, all plants go through this process, not just corn. Additional research is now showing that in some cases, soybeans, another staple Midwest crop, contribute more moisture than corn does.  

So, the next time you’re wiping sweat from your brow during another oppressive Midwestern summer day, just know it could be the crops just letting you know they’re growing well.