[Russell Sobie]

That info is a bit difficult to find, I would agree. My understanding is that, at least in Assetto Corsa races, all temps are 21 degress Celcius and the track will start at 95% for Practice session, then go from 96 to 100% over the course of the qualification session, and then remain at 100% for the entire race. The "weather" setting is random and is aesthetic only. I don't know about time of day... that might be random as well?

It might be nice if this information was not relayed via various forum posts but instead on the Rules page or some other central location for folks so they can do exactly what Gian suggests: running laps in single player replicating race conditions exactly. From all the Lap 1 nonsense that still happens in the occasional SRS race, the more people practicing the better!