You're mostly right, but there are plenty of places in the US where the daily low temperature drops well below zero for significant parts of the year.
I guess the inconvenience with Celsius is that you're more likely to go to negative numbers? Is there a problem other than the having to say "minus ten degrees" vs "fourteen degrees"?
> It also has a finer resolution than degrees Celsius in everyday weather temperature ranges.
I'd make the opposite argument about everyday use. Most people I know would barely differentiate 25C from 26C, so there's not really a need for finer gradations. And the 10 degree increments are surprisingly convenient:
-20 (or less) dangerously cold
-10 -- -20 damn cold
-10 -- 0 winter
0 -- 10 chilly
10 -- 20 brisk
20 -- 30 hot
30 -- 40 sweltering
40 -- 50 damn hot
50 (or more) dangerously hotFrom experience I'd say a sauna with 45°C and 80% humidity is about comparable with one at 80°C and 10% humidity.
There are good arguments to be made for everyday use of Fahrenheit over Celsius. The 0-100 range in F cover pretty much all of the temperatures one is likely to experience in the USA. It also has a finer resolution than degrees Celsius in everyday weather temperature ranges.
The SI units are designed for scientific and engineering use and they excel for the purpose they are designed.