Red sky at night, shepherds delight, Red sky in the morning shepherds warning, Red sky at lunchtime???
Sadly I did not have my real camera with me so had to make do with the one on my phone, you can not really tell how dark it got, but it was enough to trigger the street lights to go on at one point.
UPDATE: it has all now cleared up, not the end of the world as some were convinced it was
