alt Hacker Newsbelow zero days are really really crazy cold and above 100 days are really really crazy hot. I don't think the fact that things occasionally exceed the 100 point "normal" range makes it less useful, if anything the out of bounds numbers emphasize the severity of the temperature. it's common where I grew up in the midwest US to hear "wow its going to be BELOW ZERO" as a way to express extreme cold
For me personally “really really cold” starts below -30°C and crazy hot is above +30°C. It’s very subjective and outside of US many areas have climate where Fahrenheit doesn’t make sense at all.