Why Is It So Humid in Iowa? There’s Not Even Any Corn, Yet!
It seems like every summer there's a point where Iowans take a step outside and say "Whoa! Why is it so freaking humid?"
Considering we skipped spring and went right into summer this year, it feels like we didn't even get a warning day for the impending humidity. We just got smacked right in the mouth with it. I took one step outside yesterday and was immediately moist, and that's a consistent thing during summers in the Hawkeye State.
According to World Population Review, Iowa has the seventh-highest relative humidity in the country at 72.4 percent. Number one, believe it or not, is Alaska at 77.1 percent.
Typically, when asking the question 'Why is it so freaking humid in Iowa?' the answer can be found in the farm product so many Iowans identify with: corn.
Otherwise known as 'corn sweat' the plant takes in substantial amounts of water and transpires the water vapor into the air. Per the National Weather Service in Omaha, an acre of corn can sweat up to 4,000 gallons a day!
According to state climatologist Harry Hillaker, who said to the Des Moines Register, "Iowa's 13.6 million acres of corn, and its nearly 9.7 million acres of soybeans, add to Iowa's humidity."
And no, you're right. There's not much for corn or soybeans at the moment in here Iowa. As shared by our Ag Director, Iowa's planting season was pretty behind schedule this year.
So, what's the deal?
Like Hillaker said, the corn and soybeans don't help, but he added the following:
We'd be humid anyway. ... The warmer the air is, the higher the capacity it has to hold moisture. That can increase very dramatically as it gets warmer.
Plus, though we don't have much for crops in Iowa right now, we did have a very dark, dreary, and rainy past few months. So, factoring in that the soil is saturated with significant amounts of water, evaporation is in full effect, drying out the soil and humidifying up the air we breathe and are surrounded by.
Mark Licht, an Iowa State University Extension agronomist told the Register last summer:
Transpiration from corn is minimal compared to the evaporation that we'll have from the soil. That will drive humidity much more than plant transpiration.
And there ya go. Corn or no corn, soybeans or no soybeans, it's going to be hot and sticky in Iowa -- at least in the summer months.