The Impact Corn Has on Humidity in the Midwest

The Corn Belt is a region in the Midwest where corn is predominately grown, and this time of year it can have an impact on weather locally.  Through a process called 'Evapotranspiration', the maturing corn crop actually helps to add moisture into the atmosphere, increasing the dew point temperature within the Corn Belt region. 

Evapotranspiration is a combination of transpiration from plants and evaporation from the ground.  As the corn crop grows and matures, it pulls moisture from the ground.  Some of that moisture escapes from the leaves of the plant and then evaporates into the atmosphere.  Evaporation occurs when water changes from a liquid state into a gas state.  Both processes work to increase moisture within the atmosphere.

Late June through July is usually when the corn crop begins to reach maturity, which is when evapotranspiration is at its highest.  The hotter the air mass is, the more moisture it is able to hold.  Dew point temperatures over the weekend were very high, reaching the mid and upper 70's, and are expected to rise into the mid 70's Wednesday and Thursday.  With some of the corn beginning to tassel, the process of evapotranspiration will slowly begin to decrease, which begins mid to late August and September.