The scheduled start time of Sunday's Miami Grand Prix has been moved three hours earlier amid the threat of thunderstorms in Florida.
The race had originally been scheduled for 9pm UK time (4pm local), but following qualifying on Saturday, F1 and the FIA announced a new start time of 6pm UK time (1pm local).
The latest forecasts suggest there will be rain in the morning before storms arrive mid-afternoon and remain throughout the evening.
Florida laws recommend the suspension of outdoor sports events immediately upon the sound of thunder, with resumption not allowed until 30 minutes after the most recent clap of thunder or lightning strike.
A joint statement from the FIA, FOM and the Miami Grand Prix said: "Following discussions between FIA, FOM and the Miami promoter, the decision has been taken to move the start of Sunday's Miami Grand Prix to 1pm local time in Miami due to the weather forecast that is expected to bring heavier rainstorms later in the afternoon close to the original planned race start time.
"This decision has been taken to ensure the least amount of disruption to the race, and to ensure the maximum possible window to complete the Grand Prix in the best conditions and to prioritise the safety of drivers, fans, teams and staff."
World championship leader Kimi Antonelli claimed pole position for Mercedes on Saturday after seeing off the challenge of a resurgent Max Verstappen, who took second for Red Bull.
That represented a turnaround in form after McLaren had dominated the Sprint events, with reigning world champion Lando Norris leading a one-two from team-mate Oscar Piastri.
The last time the FIA changed a race start time was at the 2024 Sao Paulo Grand Prix, when the event was also moved earlier amid a similarly concerning forecast.
If it is wet, there are restrictions to the cars after they were revamped for this year with new regulations. Straight Line Mode, when the front and rear wings open on the straights to have less drag, will be banned, as is Boost Mode, so the cars will be unable to deploy the extra 350kW in power out of the corners.
Pole-sitter Kimi Antonelli has struggled with his starts so far this season, with the latest example coming as he dropped from second on the grid to fourth on the first lap of Saturday's Sprint in Miami.
While rain is rarely seen as ideal for a pole-sitter, Antonelli appeared enthused by the prospect of a rolling rather than stationary start, which could be used if conditions are wet for Sunday's race.
Antonelli told Your Site F1: "If it's a rolling start, definitely it will take that (standing start) element out of the way, but let's see.
"Obviously it's meant to be raining a lot, so let's see also with timings what's going to happen. Hopefully we're going to be able to find the best timing in order not to have crazy conditions."
Given there have been just three races in F1's all-new cars for 2026, the majority of the field have had very little, if any time driving their new vehicles in wet conditions.
Antonelli added: "For sure it's going to be slippery in the wet, if there is any, and it's not going to be easy also because everyone has so little experience, and some of us even don't have any experience in the wet.
"It's going to be quite a new challenge for everyone."
Red Bull's Verstappen, who starts on the front row for the first time this season, said: "I've driven them [in the wet], of course, in Barcelona [during pre-season]. I think it was only me and Charles that day, we were driving, so yeah, it was quite lonely.
"It's quite a handful. It's not going to be easy. But let's first also wait and see how much water is going to come down, because that also makes a big difference."
Piastri, who starts seventh, quipped that McLaren "probably [need to] build some oars first".
He added: "I've not looked at the forecast but everyone's spoken about it the whole weekend, so I'm just going to roll with that.
"We'll see what we get. If it is wet, that's obviously going to throw in a lot of spanners in the works because no one has really driven these cars in the rain, and no one really knows what they're going to do. So, hopefully we're on the right side of that."
Ferrari's Lewis Hamilton, who is sixth on the grid, has more experience of driving the new cars in the wet than most after he completed two days of bespoke wet-weather testing for Pirelli at Fiorano during F1's enforced April break.
Speaking on Thursday in Miami, Hamilton said: "I've definitely done more wet testing than probably ever before. I had a whole day in Barcelona, which was not fun, and then I had two days of wet testing two weeks ago."
Sunday May 3
2.25pm: F2 Feature Race
4pm: Miami GP build-up: Grand Prix Sunday
6pm: THE MIAMI GRAND PRIX*
8pm: Miami GP reaction: Chequered Flag*
9pm: Ted's Notebook*
*Also on Your Site Main Event
Formula 1 is in Miami as the 2026 season resumes, watch live on Your Site F1 with Sunday's Grand Prix at 6pm.
