Since the CRB doesn't seem to specify it (maybe some other book, like Undead Slayer Handbook or others, say more about the matter, but I don't have them), am I supposed to treat a cloudy day (the avreage grey day) as if light is normal, rather than bright? Same for shadows, like the shadow of a big building on a clear day.
And for things like a Vampire's weaknesses or a monsters' Light Blindness/Sensitivity, are they safe, as long they don't have line of sight (basically) with Sun? This would allow a Vampire to walk the streets by day, as long as it avoids open spaces where there aren't shadows big enough.
Or are they affected anyway, so long as they're under the open sky by day, regardless of clouds or shadows?
alleys can be dark even during the day
A forest canopy reduces bright light to normal light
A vampire requires direct sunlight to destroy it, so it can move about in normal light
light blindness and sensitivity only comes into effect on bright light
Actual light levels are to an extent a GM judgement call. A lightly clouded summers day is probably still bright light. Storm clouds from horizon to horizon can be normal light all the way down to dim light.
Alleways are likely to be normal to dim unless the sun is directly overhead.
A smart vampire can probably move about safely during the day in a city that it knows well if it is careful, but it is risky.