Eastern Illinois, as far north as Chicago, saw the rare appearance of the remnants of a hurricane. The leftovers of Irma reached the upper Midwest, producing a cloudy sky and even a few rain showers in Illinois.
We don't see the remnants of hurricanes or tropical storms that often, but it can happen. If the storm is strong enough and has enough moisture, it can hold on for a while, despite being away from its fuel source of the warm, humid air over water. Irma is a great example- despite being a few days away from making landfall, the weakening area of low pressure keeps producing rain as it moves over the Midwest.
There is about a 10% chance each year that the leftovers of a tropical cyclone reach northern Illinois, which averages out to once every nine years. The results of the remnants reaching the area vary. Sometimes, clouds and not much else move through. Other times, strong winds and heavy rainfall can be the result.
Notable events in our area include the leftovers of Hurricane Carla in 1961, which dropped over 5 1/2 inches of rain. In 2008, hurricanes Gustav and Ike were almost back-to-back, moving by 8 days apart and producing 5 inches of rain between the two storms. 2008 was already a very wet summer, to the two remnants did not help matters whatsoever. Ike dropped over 8" of rainfall in Chicago!
Rainfall isn't the only impact. As Hurricane Sandy started dying down as it moved westward, its influences managed to move westward enough to produce not blustery winds here northern Illinois. Rockford experienced wind gusts around 40 mph, with 50 to 60 mph gusts around Chicago and northern Indiana. Wave heights were over 20 ft on Lake Michigan, causing plenty of lakeshore flooding.
The most recent occurrence was Hurricane Isaac in 2012, but barely any rainfall fell locally.