Where do you get your weather info from?
I just drove in Valencia and it said all day long, that it would be dry, maybe cloudy. But right after the race start it started to rain until the last lap, where it was dry again. I looked at two different weather pages and both said there would be 0% chance of precipitation and during the race they said nothing of rain, either.
I think this was just bad luck. The weather forecast is only updated daily. It turns out that it rained for 45 minutes that day at Valencia, exactly when your race was on. So even though the forecast was wrong, it wasn't completely innaccurate considering that it was dry for the rest of the day.
