MN called and said let us know when those are air temps and not windchills.

Yes, Chicago is a deeper cold for longer time. If you really want to experience winter head a little farther to St Paul MN. Once you spend a weeks time of highs in the sub zeros it amazing how easy 10 degrees and sunny becomes t short weather.

Good news is when you hit forty below one no longer needs to convert between Fahrenheit and Celsius.