One of Ohio’s most popular crops is intensifying humidity and heat in Greater Cincinnati this week.
That’s due to a phenomenon called “corn sweat,” also known as evapotranspiration. Like all plants, corn absorbs water from the ground with its roots, then releases water into the atmosphere through its leaves.
Nate McGinnis is a meteorologist at the National Weather Service in Wilmington, Ohio. He says this process happens very efficiently with corn – an acre can release 3,000 to 4,000 gallons of water into the atmosphere a day.
“So, when you are releasing that much water vapor into the lower atmosphere — especially where we are living — it increases the humidity levels,” McGinnis said.
He says while large-scale weather patterns are ultimately behind the heat felt across the Midwest this week, corn sweat is adding to the effects.
“Basically what it does is it takes the normal and it takes it to a higher level,” McGinnis said.
More than 3 million acres of farmland in Ohio are used to grow corn, according to the state’s Department of Agriculture.
The crops sweat every summer. McGinnis says the wet conditions this year may mean the phenomenon is more prominent.
“It has been a particularly wet summer with lots of thunderstorms and there have been reports of flooding throughout the summer, and so the corn crop is currently very healthy, and that helps with this process,” McGinnis said.
Corn sweat happens through the corn growing season.
How to stay safe in the heat
Much of the Tri-State is under a heat advisory until 8 p.m. Friday. Heat index values could get up to 103 degrees, according to the National Weather Service.
The NWS recommends taking precautions to stay safe:
- Drink plenty of fluids
- Stay in air-conditioned rooms. If you don't have access to air conditioning, Cincinnati Rec Centers serve as cooling stations during the day
- Stay out of the sun
- Check up on relatives and neighbors
Take extra precautions when outside:
- Wear lightweight and loose-fitting clothing
- Try to limit strenuous activities to early morning or evening
- Take action when you see symptoms of heat exhaustion and heat stroke, like dizziness, nausea, or becoming unconscious.
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