July has already been more humid than average, and now another, less obvious factor will enhance humidity this week: corn sweat. Like a person breathing, corn exhales water vapor through its leaves — a process called evapotranspiration — which exacerbates humidity in agricultural regions during the summer.

The heat wave baking the central United States this week may feel worse than those earlier in the summer, and corn is partly to blame, forecasters say.

The showers and storms will fade away this evening, with quiet conditions overnight. Expect morning temps in the mid 70s. Some drier air moves in starting Thursday. This will lower coverage of rain and storms some, but many areas will still see rainfall. Highs for Thursday will be in the low 90s.