Saturday will be the best day weather-wise at Road America, with mostly sunny skies, and only a very small risk of an isolated afternoon shower or storm. Saturday will also be the warmest day of the event with the high hitting the mid 70s, after starting off in the mid 50s when the gates open. Winds will be out of the west at 5-10 MPH.
Sunday will have a chance of showers and thunderstorms at Road America throughout the day. Skies will be mostly cloudy otherwise, and the high will top out in the lower 70s. Winds will be starting out of the west at 5-10 MPH, but will be shifting out of the southeast by the late morning.
Have an umbrella handy and pay attention to the PA announcer. Road America does a great job in alerting fans and teams of inclement weather. But don't let that deter you from attending the great racing action. Rain only makes the best drivers in the world shine, and you'll have an opportunity to see that happen. Radar will be up and running by Friday morning.