It's in the northern sky. I first saw it at 8pm, it was still the same an hour later. I can't see the northern sky clearly where I am now, but it's coming up to 1am and I can still see a red glow in the same place (it's more pinky red than the photo shows).
Any idea what it could be? I'm assuming it's not a natural phenomenon given it hasn't moved or changed. I'm reminded of that tomato factory incident, but I don't know of any tomato factories in the area.
Edit: solved. It was coming from Spurs stadium and is probably lights to speed up grass growth.
I'm leaning towards it coming from Spurs stadium. I've never seen anything like this before. It was a big pinkish-red haze that didn't move or change in any way. Maybe the stadium was projecting something up into the sky all night. I'll check if it's back after sunset.