Ahead of today's all-important qualifying session, the air temperature is 33.5 degrees C, while the track temperature is 53.6 degrees. There is a 20% chance of rain.
We say "all-important", because, by the look of things, overtaking is going to be nigh impossible here, despite the three DRS zones.
Other than being very narrow - worryingly so when you consider the size of these cars - the track is bumpy and there is virtually no grip should you venture off the racing line. Add in those ever welcoming barriers and you have a recipe for disaster.
With every practice session interrupted by at least one red flag stoppage we see no reason why that will not continue over the next hour and into tomorrow.
And then there's traffic...
Consequently, despite the fact that Red Bull and Ferrari head into the session as favourites, the fact is that anything can, and probably will happen.
The various interruptions have also limited the amount of running on high fuel but the impact of this will be felt tomorrow, nonetheless we are expecting a few shocks and surprises over the next hour.
The big disappointment earlier is that Mercedes appears to have taken a step backwards, the dreaded porpoising far more noticeable than yesterday.
Other to watch out for are Alonso, Bottas and the Haas pair.
Despite its best intentions, following his crash earlier, Alpine has revealed that Esteban Ocon's car has suffered a cracked chassis, therefore the Frenchman is ruled out of the session.
And then there were 19.
The lights go green. Magnussen is first out, followed by Schumacher, Albon, Vettel, Tsunoda, Gasly and Stroll.
Leclerc is among the early risers, like the rest he is sporting softs.
Magnussen gets proceedings underway with a 33.148, but a 32.495 sees Albon go top.
Vettel posts 32.212, Tsunoda 31.944 and Stroll a 31.789.
Sainz is the first of the big guns to post a time, the Spaniard crossing the line at 30.858. Moments later Leclerc posts 31.349, but Ricciardo leapfrogs the Monegasque with a 31.275.
Gasly has his time deleted for exceeding the track limits at Turn 13.
Verstappen goes top with a 30.235 and his teammate second with a 30.778.
Russell goes third with a 30.807as Hamilton aborts his first flying lap.
Next time around the seven-time world champion posts a 31.550 to go 12th.
A 31.020 sees Zhou go fifth, ahead of Ricciardo, Leclerc, Alonso, Schumacher and Norris.
Hamilton very scrappy, the Briton is clearly (still) not as comfortable with the W13 as his teammate.
As Magnussen goes seventh, Leclerc goes quickest in the first two sectors, as Sainz goes quickest overall with a 30.079. However, Leclerc subsequently crosses the line at 29.474.
Verstappen improves (29.836), but can only mange second, 0.362s off Leclerc's pace.
Alonso goes eleventh, ahead of Zhou and Schumacher, the Spaniard having brushed the wall at Turn 15.
With 5:00 remaining, Hamilton is in the drop zone, along with Gasly, Latifi, Albon and, of course, Ocon.
Hamilton stops and takes on another set of softs, as teammate Russell falls down the order to eighth.
Albon improves to 14th with a 31.266 but is demoted when Tsunoda goes fifth and Gasly 10th.
A 30.490 sees Russell improve to 6th.
As was the case in Imola, Hamilton finds himself at the tail of a long train of cars, some on flying laps others on out laps.
He posts a PB in S1 and another in the second sector. At the line he posts 30.388 to go fifth, which should be enough.
A massive traffic jam in the final sector costs Zhou any chance of improving, while Alonso also looks likely to miss out.
"So many cars blocked me on my flying lap," says the Chinese driver, "we need to report this, it is very dangerous."
Norris doesn't improve on 11th, as Stroll goes sixth.
Alonso does improve, he goes sixth with a 30.407, while Vettel posts 30.677 to go 12th.
A late improvement also sees Perez go third with a 30.055.
Quickest is Leclerc, ahead of Verstappen, Perez, Sainz, Hamilton, Alonso, Stroll, Tsunoda, Russell and Ricciardo.
We lose Magnussen, Zhou, Albon and Latifi.
Ahead of Q2, Schumacher waits patiently at the end of the pitlane. He is subsequently joined by Leclerc, Sainz and Bottas.
Schumacher posts a 30.423, but this is almost instantly beaten by Leclerc (29.754) and Sainz (29.729).
As Bottas goes fourth with a 30.605, Verstappen posts a 29.202 and Perez a 29.673 to make it a Red Bull 1-2. Used softs very much the order of the day... for now.
Hamilton goes fifth with a 29.797, ahead of Norris (30.289), while Ricciardo posts a 31.129 to claim ninth.
Perez reports that he's losing traction in the final corner.
Gasly goes sixth and Tsunoda seventh, as Stroll posts a 30.363 to go ninth.
Bottas improves to seventh with a 30.237.
Alonso goes 8th and Vettel 13th, as Russell, the only driver yet to post a time, finally heads out.
"****, bouncing," reports Russell who is on new softs.
Leclerc retakes the top spot with a 29.130 while teammate Sainz fails to improve on his previous best and remains 4th.
His next flying lap sees Russell post 3.173 to go seventh, but is it enough?
With 3:30 remaining, Norris, Stroll, Schumacher, Vettel and Ricciardo comprise the drop zone.
On board with Hamilton and he's really struggling. He fails to improve on fifth.
PBs in the opening sector for the Aston Martin pair and Bottas. Norris has upped his pace also.
Vettel goes eighth (30.214), but is demoted when Stroll goes seventh. Bottas goes fifth while Russell pits.
"Argh no, I lost it in the chicane," moans Vettel.
Norris goes third and Tsunoda ninth, which is bad news for Alonso.
PBs in the first two sectors for Ricciardo are followed by a third, however, the Australian can only manage 14th and therefore fails to make the cut.
Quickest is Leclerc, ahead of Verstappen, Norris, Perez, Sainz, Bottas, Hamilton, Stroll, Tsunoda and Gasly.
Told he is P9, Tsunoda responds: "Let's go, let's go. I'm happy, let's go!"
We lose Alonso, Russell, Vettel, Ricciardo and Schumacher. A big surprise to see the Australian fail to make the cut since he has looked strong in the previous sessions.
Check out our Saturday gallery from Miami, here.
sign in