Southwest Indiana and southeast Illinois have seen their share of fog this month, and weather experts say some of it is known as “corn fog.”

Caleb Ivins with the social media page Indiana Weather Online explained that the phenomenon occurs when corn plants release large amounts of moisture into the air during the summer. That moisture can create fog when conditions are right.

“Corn is a highly efficient plant at moving water through the plant and into the air called transpiration,” Ivins said. “Transpiration is similar to how we sweat on humans. A single acre of corn plants can release 3,000 to 5,000 gallons of water per acre under ideal conditions.”

Corn fog is usually shallow and patchy, often forming in valleys and over fields during the early morning hours.

Ivins also addressed a long-standing weather saying that the number of foggy mornings in August predicts the number of snowfalls in winter.

“I’ve heard that, too. I’d say we’re in for a good winter, but unfortunately there’s just not a lot of scientific background to really back that theory up,” he said. “But it is a good theory, and for winter lovers, I’m sure it’s a wishful, hopeful theory as well.”

Looking ahead, Ivins said his page is forecasting what he calls “Fake Fall #1” beginning early next week, with daytime highs dropping into the 70s and overnight lows in the 40s.