I would also hazard a guess that the closer to the horizon the Sun is located, the more atmosphere it needs to cross to reach you (because of the lower angle) w

I would also hazard a guess that the closer to the horizon the Sun is located, the more atmosphere it needs to cross to reach you (because of the lower angle) which results in higher absorption rate before it reaches you (simply said, it's a bit darker the closer you get to the poles). I'm mostly guessing though, so please correct me. ps: I remember seeing the sun in northern Norway at midnight in the summer long time ago when I was visiting. Was just a little bit brighter than the moon usually is. pps: This is the same effect as what the sun looks like just before sunset around the rest of the world.