FYI, none of this has ever made any sense at all to somebody who didn’t grow up with Fahrenheit. Numbers don’t need to go roughly between 40 and 100, and then occasionally 212 and 450.
The difference between 20 C and 20.5 C is not generally noticeable. The difference between 20 and 25 really is.
You’ll just have to face the fact that you feel comfortable with a really weird system that nobody else can see the point of, but it’s what you’re comfortable with. That’s OK, you’re allowed.
It's common here to say something like "this week it's in the 70s." In places that use Celsius, "in the 20s" must be too broad, so do they instead say something like "high 20s"?