According to Weather.com the forecast for Earlville, IL 60518-
Thursday Day: High of 87, Scattered Strong Storms/Winds, Precipitation: 50%
Thursday Night: Overnight Low, 66, Strong Storms, Precipitation 80%
Friday: High 78, Low 59, PM Thundershowers 60%
Saturday: High 83, Low 63, Mostly Sunny, Precipitation 20%
I think packing for rain would be advisable. But, if that pavillion is gonna be rockin, there will be a dry feast, I hope.