Humidity from Corn Sweat Intensifies Extreme Heat Wave in U.S. Midwest
“Corn sweat” further aggravates this heat wave
The wet heat is covered in the East of the United States this week, exacerbated by “corn sweat” in the Midwest
Heatrisk’s forecasts for July 23, 2025.
National Meteorological Service / Noaa
The heat and humidity will once again suffocate half of the country this week, pushing the heat index at dangerous levels for tens of millions of people. In the Midwest, humidity will be stimulated by a phenomenon called “corn sweatshirt”.
It is in the middle of the summer, so heat and humidity are quite standard in the country’s most wet half in the country. It is unlikely that this heat wave beats records, but it could always be dangerous, explains Bob Oravec, chief forecastist of the National Weather Service office in College Park, MD.
[Read more: Heat Is More Than Just Temperature—Here’s How We Measure It]
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On Monday, heat and humidity are centered on the southeast and along the Gulf coast. In the middle of the week, they will move north along the Mississippi valley and go up in the Midwest before moving to the Mid-Atlantic and the Northeast towards the end of the week. The summits should be approximately 95 to 100 degrees Fahrenheit (35 to 38 degrees Celsius) as the heat wave moves, but humidity means that it could feel closer to 110 degrees F (43 degrees C) in the most affected areas. Large stretches in the east of the United States will be made in the “major” cleat category, an NWS classification which incorporates heat, humidity and data on the moment when heat linked to heat tend to increase in a given area. The pockets will be in the “extreme” category, the highest on the four -category scale.
Part of the reason for oppressive humidity is that “the meteorological model has been favorable to wet weather,” explains Oravec. “Everything is wet, saturated”, which means that there is more evaporation of the soil and the perspiration of the plants. This is particularly true in Midwest, where huge fields of corn, soybeans and other crops release humidity when the temperature climbs. The process is similar to the way humans reveal the heat, hence the nickname “corn sweat”. “The Midwest is famous for the high points of the dew of the vegetation,” explains Oravec.
Aside from plants, the phenomenon has serious implications for humans. High humidity and heat increase the risk of heat disease – it is more difficult for the body to cool by sweating because the air is already so full of humidity that sweating does not evaporate. These concerns are particularly high for risk groups such as young children, the elderly, those who have various health problems or who take certain drugs, people who work outside and without difficulty.
Prolonged exposure to such conditions can cause heat exhaustion, which can cause fatigue, dizzy, nausea and a cessation of perspiration. If a person with this condition does not reach a colder location or does not receive treatment quickly, the exhaustion of heat can progress in a heat stroke, which causes their ability to cool, an extremely dangerous situation. In fact, it can be fatal.
Experts are waiting for people to stay hydrated and avoid intense outdoor activities, especially in the middle of the day, when temperatures are highest. There are also advice to keep your home cool. [Read more: Six Ways to Stay Safe Outdoors in Extreme Heat]
These concerns will persist in the short and long term. In the long term, heat waves become warmer and occur more frequently than in the past due to the additional heat trapped by greenhouse gases in the atmosphere as a result of human fuels burning fossil fuels. An analysis of the central non -profit climate has revealed that the climate change caused by Human,, Almost half of the American population.
In the short term, weather models show damp heat in the east of the United States for the week or the next two. “The meteorological model is simply stagnant and is stuck,” explains Oravec. “It seems that it will be a few hot weeks.”
