What is “corn sweat” and how could it aggravate the dangerous heat feeling all over the Chicago area this week?
The whole north Illinois is under a heat warning for Tuesday, but a phenomenon known as “corn sweat” will make conditions even more challenging in areas away from the city of Chicago.
Here’s what it is and how it might affect you:
What is corn sweat?
According to the Weather Channel, “corn sweat” refers to a process by which plants exhale water, the technical term for which is “evapotranspiration”.
Officials say the process peaks between mid-July and late August, with each acre of corn potentially releasing up to 4,000 gallons of water per day.
What does this mean for weather in the Chicago area?
Heat indexes could hover above 110 degrees and could even approach 115 degrees in some parts of the state on Tuesday, according to an overheating warning issued by the National Weather Service. Because heat index is calculated using dew points and temperatureanything that adds extra moisture to the air can affect them.
And that’s where “corn sweat” comes in.
The phenomenon adds extra moisture to the atmosphere, which can drive up dew points in areas where there is a lot of agricultural land.
In the Quad Cities, for example, the heat index reached nearly 110 degrees Monday afternoon, with air temperatures in the low 90s and dew points reaching a steamy 80 degrees.
The entire state of Iowa was under an excessive heat warning on Monday and will see similar conditions on Tuesday as the high humidity combines with some of the hottest air temperatures of the season.
Iowa is ground zero for “corn sweat” affecting conditions, but parts of Missouri, Minnesota, Wisconsin and Illinois may also be affected.
What else to know about corn sweat
According to the National Weather Service’s central Illinois office, mature Illinois corn crops “release over 35 billion gallons of water daily into the atmosphere.”
That’s enough water to fill over 52,500 Olympic-size swimming pools, the agency noted.