And yeah, when the smog settles in it looks like a low cloud. Visibility can get down to a couple of hundred meters. It's not totally permanent (e.g. last night it was windy and so the air is clear this morning), and the summer is usually clearer, but during the winter in particular you can only ever see so far before it all goes grey. It is more often than not that I can't see the mountains that lie on the west and north edges of the city.
It's even visible by satellite:
