Apparently the aurora borealis came all the way down to the middle of the U.S. earlier this week. With a little probing, I found the University of Alaska aurora forecast page. Tonight, we probably won't see the aurorae in Chicago. But there's a huge sunspot right now, so possibly we'll see one later in the week.
Here's the self-updating NOAA map. The bright area shows the current aurora; the red line points to the sun.