Dangerous heat continues across the U.S. as millions see feels-like temperature reaching into the 90s and 100s from the Southeast to the Midwest.

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.

Heading into Wednesday night, the comfortable nights are over, the humidity is still rising, and with lows in the low 70s, overnights will start feeling similar to how last week was. Skies will remain mostly clear throughout the night.

TODAY: The weekend starts dry, with temperatures quickly rising to the upper 80s and low 90s by early afternoon. The heat index reaches the low triple digits, between 100 and 103 degrees. Scattered storms then develop during the heat of the day by midafternoon,

Another heat dome is moving over Illinois this week as temperatures near the triple digits. Here's what that means and when we can expect relief.