Chilean 'Sunset'

This evening, I noticed my apartment was bathed in an eerie orange light. I figured, "that's just the sunset", but there's a problem: my apartment faces East, not West. I see sunrises, not sunsets.
I had a look outside, and this is what I saw:

I'll have to post another picture on some other day so you can see how unusual this is; it's usually far clearer (Update: see here for another, much clearer anti-sunset). This image also fails to capture the eerie glow all over the place.

Now part of that is just clouds coming in from the East over the Andes, but the part near the ground: I'm not too sure. The most likely culprit is smog, as this is extremely common here in Santiago. I've never seen it like this towards the East, though: it usually is worse (and clearly smog) looking West or South as this is where the densest parts of the city are, relative to where I live and work.

Still, it seemed appropriate at the time considering I'm ~70% done with Un Lun Dun, whose bad 'guy' is Smog itself.