Timmy!

So it looks like you want the following for the "best" racing conditions:
Low Temp
Low Humidity
High Pressure

But you also want a sunny day to keep the track warm

robz

Barometer and temp play the biggest role as well as the altitude in determining DA and how much power the car is putting out. Humidity plays a lesser role despite popular belief. Often times when the humidity is high so is the temp which is more of a factor.