I call BS. Most of the time when I see Americans talking about temperature, they don't use exact numbers but rather group them into stuff like "low 80ies" or "high 60ies". Do you feel any difference between 62 and 63 F?
Well, when the forecast tell me to expect -22 C in Oslo, I know that it won't be -22 C where I live in Oslo, but I can guess what it will be like, probably a little colder depending on wind speed, direction, etc. If the forecast just says somewhat below -20 C, it makes my interpretation harder.
But more important is if the forecast yesterday was -20 C, I know it is expected to be colder today. Not much, but still. This isn't possible if you get the same forecast every day because you neither can predict accurately, nor feel the difference.