Ahead of today's sole practice session the air temperature is 27 degrees C, while the track temperature is 44 degrees. As was the case yesterday, it is bright and sunny.
Following yesterday's sessions it remains difficult to pick a true pecking order, though Max Verstappen looked good in FP2 following numerous issues in the first session.
At Mercedes Lewis Hamilton appears pleased with the W14 upgrade, though teammate George Russell had problems switching his tyres on.
Ferrari looked strong, Charles Leclerc looking understandably cautious considering his record here, while Carlos Sainz was one of several drivers to come to grief over the course of the day, the others being Hulkenberg and Albon.
Of course, all eyes are on Fernando Alonso however the Spaniard is keeping his head down and getting on with the job.
Other than traffic which going to be a problem in Q1 as ever, the unforgiving nature of the circuit is likely to throw up some surprises, and while drivers know that overtaking is almost - that's almost - impossible, better to start from 11th or 12th then stuff it in the barriers and end up starting from the pitlane.
The lights go green, but it is a couple of minutes before the first driver (Stroll) appears. He is followed by his Aston Martin teammate.
While the Canadian is on mediums, Alonso is on hards.
As the Alphas head out, Stroll pits and switches to hards while Alonso switches to mediums. No, us neither.
Perez and the Alpines head out on softs, as drivers follow the Aston Martin example of doing the one lap then pitting.
Oh dear, Ocon stops in the tunnel. "I have no power," he reports, before finally getting going again.
Meanwhile, Perez posts the first time of the day, a 15.641.
As he slowly makes his way back to the pits, Ocon warns his team to have the fans ready for the rear brakes.
Gasly goes second with a 28.664.
As Ocon finally arrives back in the pitlane the session finally springs into life as the Ferraris and several others head out.
Bottas goes second (15.946), ahead of Gasly, de Vries and Zhou.
Perez improves to 14.990 as Norris - who had a good second session yesterday before encountering a technical issue - posts an 15.841.
A 15.056 sees Sainz go second as Verstappen, Sargeant and the Silver Arrows remain the only no-shows.
Stroll goes third and Leclerc sixth, but both are demoted when Norris goes quickest with a 14.905.
Encountering traffic in the second sector, Alonso aborts his first flying lap as his teammate goes quickest (14.763).
"This year, the tyres only really have one good lap in them," says James Vowles, "and that's going to make qualifying a real challenge. Normally you'd put fuel in for the whole session, as if the session was wet. You are seeing this pattern with everyone, more so with the faster teams."
Finally getting some clear air, Alonso goes third with a 14.602, but is instantly demoted when Verstappen - on his first flying lap - bangs in a 13.794.
"Can you let me know if I touched the wall in Turn 14," asks Leclerc, "I think I did but because the wall is soft I couldn't really feel it," he adds. The youngster is subsequently given the all-clear.
Quickest in the opening two sectors, Alonso crosses the line a 13.697 to go top, 0.097s up on Verstappen.
Russell's first timed lap is a 23.481, as teammate Hamilton finally heads out, almost 20 minutes into the session.
As most switch to the red-banded rubber, Perez raises the bar with a 13.587 as Russell improves to fourth with a 14.382.
Verstappen out-paces his teammate by 0.004s.
Hamilton's first flying lap sees the Briton go 15th (14.675), the Mercedes driver encountering heavy traffic.
Russell improves to fourth and Ocon fifth, as Leclerc improves to seventh.
No sooner has Perez raised the bar with a 13.289 than his teammate responds with a 12.898.
Leclerc is unhappy with turn-in, particularly at the entry to the Swimming Pool, which is where he had his close encounter earlier. The youngster also complains of bottoming.
"We need to change the car," says Leclerc, "I have to lift in the Swimming Pool because I have no control of the car."
Perez posts a 12.849 but once again Verstappen responds, this time with a 12.776.
Hamilton goes fifth with a 13.552, as Russell has a "hefty" hit of the wall at Rascasse. "I think it's OK," he adds as he subsequently pits.
With 22 minutes remaining, Albon, Hamilton and Gasly have the track to themselves... luxury.
Stroll, who has had a change of front suspension, goes quickest in S2, the Canadian finally crossing the line at 12.942 to go third.
The qualifying sims are underway.
Piastri can only manage 14th (13.998), as Norris misses the chicane and has to abort his lap.
A 13.650 sees Hulkenberg go eighth, while Sainz remains fourth after making a mistake in the final sector.
Clearly struggling for grip, Alonso's first flaying lap sees him well off the pace in the opening sector. Encountering traffic, Verstappen aborts his lap.
Norris goes fifth with a 13.396, just ahead of Gasly.
Again, Verstappen aborts, this time after losing time behind a slow Ferrari on the run up the hill.
Magnussen takes to the escape road at Ste Devote and makes a complete pig's ear of extracting himself.
Having finally got going, Magnussen has an issue. "Stop the car, stop the car," he is told, the Dane parking-up at the entrance to the Tunnel.
Alonso goes quickest in S1 at which point the VSC is deployed.
The all-clear is given with just over six minutes remaining.
"How far are we down?" asks Hamilton. No sooner is he told "P8" than he loses the rear of the car and slides into the barriers at Mirabeau. He had just gone quickest of all in the opening sector.
The session is red-flagged.
Judging by the way the marshals are struggling to extract the car the Mercedes is fully wedged into the barrier.
The session will not resume.
A frustrating end to the session, which sees Verstappen quickest, ahead of Perez, Stroll, Sainz, Norris, Gasly, Leclerc, Hamilton, Ocon and Bottas.
Russell is eleventh, ahead of Magnussen, Hulkenberg, Alonso, Tsunoda, Zhou, Sargeant, Albon, Piastri and de Vries.
Check out our Saturday gallery from Monaco here.