Lewis Hamilton says the drivers could go into Sunday's Monaco Grand Prix "blind" in light of their limited running on the dry Pirellis on Thursday.
The weekend's first two practice sessions are traditional the time spent getting to know the track and the tyres, especially in the afternoon session when teams often concentrate on longer distance runs.
However, with rain coming down on Thursday afternoon this was not possible.
Instead of spending 90 minutes trying to understand the unpredictable Pirelli tyres, the drivers spent at least 30 of that in the pits trying to stay dry before finally heading out on intermediates.
"It was a difficult day in terms of trying to dial in the car because of the conditions changing and there was also a lot of traffic out there," said Hamilton.
"It was still incredible driving this track. I saw some on-board footage of a Red Bull, and I hope people saw how violent it is in the car. It is so bumpy, but it is so much fun.
"The problem is the less running you do then the tougher it is to understand the tyres, and no one managed to do a long run.
"They might do one in FP3, but I doubt it, so everyone will be going into the race blind in terms of how the tyres behave.
"I'm sure it will be a big surprise for everyone. We're all in the same boat, so it will be fun that's for sure."