These photos are from August 28, 2004, which was qualifying day for the Belgian Grand Prix. Since it rained most of the day, the drivers qualified on rain tires. The race, which was the next day, took place under a clear sky. Because of Formula 1 regulations, these drivers were forced to start the race on the tires on which they'd qualified, which played havoc with everybody.
In these shots from qualifying day, the clouds of apparent smoke behind the cars is really just water being thrown up from the track.