Living by the mountains, this time of year we'll have one dat at +10C, the next at -30. Nothing consistent. I spent 7 years in the eastern arctic though, with days at -50C. The windchill wasn't even on the chart at the Flight Service Station, but on a windy day we extrapolated it to -125 lol! Nothing happened below -50. What few businesses there were remained closed. Our plane was rated to -48C, below that the hydraulics didn't work.