It's a little too nitpicky IMO to point this out (not to say you were trying to be though, all good), because what people are shorthanding here is that it's "unseasonably warm" still, and that's a good thing.

"Winter so far has been mild" is not a confusion on their part that it won't get any colder, just a misstatement. Autumn has been unseasonably warm, and the difference in parts of Europe between the two isn't as severe as here in the US.