I'm not from the area, so I'm unsure if there are severe micro-climates in or around Chicago. Maybe, even, you and your neighbor are acclimated to very cold weather conditions. It's irrelevant either way, as we would all be better served by not conflating weather with climate, which OP's post is also doing.
Christmas Day in 1983 was a record low for Chicago.
https://www.youtube.com/watch?v=WpT0vG56ADM
https://www.wunderground.com/history/daily/us/il/chicago/KMDW/date/1983-12-25
I'm not from the area, so I'm unsure if there are severe micro-climates in or around Chicago. Maybe, even, you and your neighbor are acclimated to very cold weather conditions. It's irrelevant either way, as we would all be better served by not conflating weather with climate, which OP's post is also doing.