Rain had been forecast for Sunday throughout the week, only for the chances to reduce as the scheduled start at 3pm neared.
But after clouds grew over Monaco as the pre-race grid ceremonies took place, light rain began to fall before growing in intensity, forcing teams to quickly hurry their wet tyres to the grid.
FIA race director Eduardo Freitas suspended the start procedure five minutes before the scheduled start before staying the formation lap would start nine minutes late at 3:09pm local time.
Freitas then instructed that the formation lap would start behind the safety car, meaning all teams had to switch their drivers to full wet tyres.
The start was then delayed again, this time to 3:16pm local time, as the rain continued to grow in intensity. Race control again instructed the formation lap would start behind the safety car with all drivers on the full wet tyres.
“Race control was monitoring a severe downpour that was rapidly approaching the circuit, and as it arrived during the start procedure, the safety car start and its associated procedures were implemented,” the FIA said in a statement explaining the call the delay the start.
“This was done for safety reasons in consideration that there has been no wet running this weekend.”
But completing the first formation lap, the safety car stayed out and continued to lead the field around, before race control took the call to red flag the race during their second lap around at 3:20pm after the rain grew heavier in intensity.
A number of drivers reported the rain had got much harder during the formation laps, and returned to the pit lane when the race was red flagged, with teams erecting tents to keep the cars dry during the stoppage.
Mick Schumacher told his engineer that he had “never got this wet in a Formula 1 car ever”.
The race will start on a 10-minute warning from race control.
