Just saw it in downtown Chicago (by the lake). Faint, but visible with naked eye. Easier to capture with my pixel 8 than with my (handheld) DSLR, even with a fast lens...kicking myself for not grabbing my tripod
Fellow Chicagoan here! I went down one of the piers and saw it as well. At first it looked like cirrus clouds but the colors emerged as my eyes acclimated. I thought it was my brain hallucinating the details it expected but my phone validated what I was seeing. Truly stunning even with just a 2sec exposure.