Many drivers & teams, after 2 days of mostly damp conditions, are relieved that the forecast for the Rolex 24 At Daytona is for partly cloudy to sunny conditions.
The corollary to that is that once the clouds clear this evening, it’s going to get very cold. Making for the coldest Rolex 24 ever.

Depending on which forecast you’re looking at, the highest temperature of the race will be about 50 degrees F (9 degrees C) about the time of the checkered flag.
The low will dip to just below freezing around 7 a.m.
Aside from concerns for keeping crews and drivers warm, the big concern over the weather for the Rolex is tires.
While the out-laps are going to be tricky and cold tires will certainly catch some drivers out, there do not to be any concerns for safety otherwise.

“With what’s currently forecast, we’re still confident that the tires will perform,” said Hans Emmel, WeatherTech SportsCar Championship manager for Michelin. “Obviously, they could take a little bit longer to warm up to as the drivers come out on cold tires from the pits.
Certainly a lot of teams will opt to double stint when and where they can to to put drivers back out on hot tires, or maybe change two tires and not change the other two, to give them some heat in the tires as they exit pit lane and go through the the infield section of the course.”

Michelin’s bigger concern for tires, notes Emmel, is mounting the tires, which can get problematic when it gets too cold.

“If the temperatures get down to freezing, we’ve put in some provisions in our mounting facility to make sure that there’s sufficient temperature while mounting the tires. That’s really where some temperature can get tricky for us.
So we’ve enclosed some areas and warmed some areas to make sure that when the tires come out of the truck through the middle of the night, it gets it’s like an assembly line through there with teams bringing us tires back, new tires going on, we’ve put provisions in to make sure that mountability is not an issue,” he said.

According to several drivers, it’s going to take most of a lap to warm the tires up enough so that they’re not sketchy, and up to three or four, depending on class and car, to get fully up to temperature.
Not only are there likely to be numerous single-car incidents on out-laps as a result, but drivers will have to be quite aware of which cars around them may have just come out of the pits on cold tires.

“The difference of speed between cars that are on their out-laps and cars that are at speed is going to be huge,” explained No. 5 JDC-Miller Motorsports Cadillac driver Tristan Vautier. “I mean, even in the infield, a GTD [on warm tires] is going to be quicker than a DPi getting out of the pits with four sticker tires.
So all in all those situations you’re going to be exposed and if you come up to speed in a DPi on an LMP3 or a GTD with a low-experience driver on cold tires, it’s going to be very difficult as well.
So it’s going to be a lot of tricky moments.”