The boys here in Minneapolis who say such things say it’s about -14 as we speak. They, with a capital “T” who say such things claim it will be about 25 below come sunup. I believe the last time this happened was circa 1997 or 1998. I remember that because my son was around 17 going on 18 and in the BSA. We were on a winter expedition.
North of mpls. My phone says -20 at the moment.