Here is the NWS radar/rain gauge product that takes advantage of good spatial coverage of radar with the accuracy of rain gauges for the last 7 days. The oranges, pink, and red, indicate amounts of 2 to 5 inches and covers much of the state. The heaviest amounts of 4 inches or more were east of St. Louis. Meanwhile the lightest amounts were in northwest Illinois were in the range of 0.25 to 0.5 inches.
Because of the 4-km resolution of this product, you can really see the large differences over small areas that is typical pattern from thunderstorms during the warmer months of the year.