I just watched The Day After Tomorrow. I'd give it 7/10.
It's standard disaster movie fare, with few surprises. Like most disaster movies, there is a love story, though it isn't really the central focus. The dialogue is preachy and corny. The science is probably wrong (or exaggerated). But it's still entertaining enough to justify forking out the money to watch it at a cinema.
This review matches up quite well with what I thought of the movie.
PS I think the movie used the Fahrenheit scale for temperature.