Inaccurate weather

In-game weather says that it isn't raining, but weather underground says that it is.  Can someone offer a better explanation of how the game bases its weather off weather underground?

Thanks!

Nothing on this?

What do you mean weather underground?
Wet track? Track still with water, even if it's not raining?

Weather Underground is the website from which iGP Manager takes forecast for races, Ricardo.
:)

Depends on the timing of the race. I know that the game "freezes" the weather at a preset time before the race starts so you don't get the issue of practicing on dry setups and then having it switch to rain with 1 minute to go before lockdown.

Thanks for the responses.  

Teo, does the game later unfreeze the weather?  Otherwise, how does it determine when it will rain?  Is that supposed to mirror real life conditions from Weather Underground's forecast?

From what I gather, the weather is unfrozen either after race preparation is locked or when the race starts. At that point, the race derives its weather data from Wunderground's current conditions.