This is the forecast for the Iowa State Fair for Sunday August 16th.

NWS: Mostly Cloudy with Showers and Thunderstorms likely (60%) 81°, South Wind 9-16mph gusting to 23.
WX Underground: Thunderstorms Likely (60%) 79°, South Wind 5-15mph gusting to 25mph
WHO-TV: Thunderstorms 81°
KCCI-TV: Periods of Thunderstorms 80° South Wind 10-20mph
ABC5: Peeks of Sun with Thunderstorms Likely 82°

Grade: C-/D+ (It won’t be raining all day, but there is likely going to be a lot of dashing into buildings (VI, Ag etc.) to get out of any approaching storms. Some of the storms could be severe as well.