It got down to -30 in DeKalb Illinois (west of Chicago) about 30 years ago when I was in college. It was so cold out it was difficult to breathe. With the wind, I think they reported that it got down to -65 degrees. It’s something everyone should experience.
I remember that. Heck it wasn’t just one day either. It was a few days in the negative double digits and then a few more days again.
My father took a picture of our thermometer at -35 about that time. In mid Missouri. But you know, I don’t even remember the cold so much. I had a blast sliding on the ice in our creek while waiting for the school bus.