It went super dark while I was swimming. I did wonder if the world would still be there when I came out. The contrast between the sky and the fluorescent lights was impressive, turned them very blue (enough to defeat my colourblindness). It's brightened a bit now and the wind has got up (and the temperature dropped), but it's still very martian.
I'm quite impressed too. If this is End Times, they really should have bigged this up. You will die and be judged, but hey, it'll look kinda cool beforehand.