Ahead of today's qualifying session, the air temperature is 14 degrees C, while the track temperature is 20 degrees.
Since this morning's session it has been raining, and although it has now stopped the track remains damp with a 90% chance of further rain.
All of which means that what we saw for much of yesterday and this morning goes out the window, which is great news as far as Perez is concerned, the Mexican having had a nightmare FP3.
As ever, what happens in such conditions is pretty much a lottery, while adding to the conundrum is the fact that tomorrow's conditions are expected to be entirely different.
Verstappen was quickest earlier, ahead of Alonso, Ocon, Russell and Gasly, with Hamilton 8th and Leclerc 13th.
The lights go green and Sargeant, one of several drivers to have had a tough time of it thus far this weekend, leads the way, followed by Albon Tsunoda, de Vries, Bottas, Zhou and Magnussen.
Surprisingly, not everyone appears keen to get to work, despite those ominous clouds overhead and the even more ominous clouds in the distance.
Albon gets things underway with a 26.458, before Bottas posts a far more sensible 20.577 and Magnussen a 19.392.
Next time around Albon improves to 18.944, as a mistake by his teammate, who clips the kerb at the penultimate corner and spins, brings out the yellows.
As Hulkenberg posts an 18.373, the big guns head out.
Oh dear, Perez' nightmare continues. The Mexican is off and in the gravel at Turn 3. His car is clearly beached as his wheels are spinning to no avail.
It's almost as if Jos Verstappen has radio control over the car... or maybe Daniel Ricciardo.
"We need to sort the issue, man," he complains, "it was the same f****** issue again."
The session is red-flagged.
With 11:44 remaining, those drivers yet to post a time, including Perez' teammate, Verstappen may regret not heading out earlier. Their cause is not helped by the fact that other than the obvious traffic, the tyres take a couple of laps before they are at their optimum.
And should there be any further stoppages...
The session resumes and Verstappen leads the way - on scrubbed tyres - ahead of Alonso, Stroll, Albon and the Ferraris.
In no time at all, all bar Hulkenberg and Magnussen are on track, and despite being first and third it is unlikely that they will settle for their current times.
Verstappen immediately goes quickest with an 18.063, while Stroll goes third and Alonso fifth.
Russell goes fifth but is demoted when his teammate posts an 18.689 to go fourth.
As Albon goes quickest in S2, subsequently improving to second with an 18.143, Verstappen raises the bar with an 18.063.
Norris goes sixth, but is demoted when Sainz goes third. Leclerc can only manage eighth.
An 18.891 sees Sargeant go tenth.
Quickest in the first and final sectors, Alonso goes quickest with a 17.832.
However, Verstappen improves with a 17.469.
An 18.091 sees Russell go fourth.
With 4:33 remaining, Sargeant, Bottas, Piastri and Magnussen comprise the drop zone, with Leclerc, Tsunoda and Zhou hovering.
Rather than pit, with their tyres seeming good for two or three hot laps the drivers remain on track.
Hulkenberg goes fifth, Leclerc ninth, and Magnussen 11th as the timing screens light up.
Hamilton goes second, but local hero Piastri remains in the drop zone.
All bar Verstappen are on track with 35 seconds remaining.
Bottas remains 19th, while Magnussen goes tenth. Sainz goes fifth, Gasly thirteenth, while Piastri improves to sixteenth but fails to make the cut.
At the death Ocon goes third, but is demoted when Russell posts a 17.654 to go second.
Quickest is Verstappen, ahead of Russell, Hamilton, Ocon, Alonso, Stroll, Sainz, Albon, Hulkenberg and Magnussen.
We lose Piastri, Zhou, Sargeant, Bottas and, of course, Perez.
De Vries leads the way as Q2 gets underway, followed by the Ferraris, Tsunoda and Alonso.
Soon all bar the Alpine are on track.
De Vries sets the benchmark somewhat low, a 27.559, before Alonso responds with a 17.681 and Stroll a 17.616.
Norris goes third and Albon fifth, the Williams driver giving a good account of himself this weekend.
Quickest in the first two sectors, Leclerc crosses the line at 17.560.
Magnussen goes fifth, ahead of Tsunoda, but both are demoted when Albon posts an 18.225.
On his first flyer, Verstappen goes quickest with a 17.219.
A 17.663 sees Hulkenberg go fifth, while Hamilton can only manage seventh (17.756).
An off for Norris at Turn 3 sees Norris have his time deleted.
The Alpines finally head out with just over 8 minutes remaining.
Alonso improves to second with a 17.283, while Sainz goes sixth.
An 18.082 sees Ocon go eighth, while Gasly's first lap is good enough for 12th.
"I don't know why the front is sliding so much," says Gasly.
Albon goes quickest in S2, as Norris goes tenth overall with an 18.185. Albon subsequently crosses the line at 17.761 to go ninth.
With 2:40 remaining, all bar Alonso are on track.
Hulkenberg improves to sixth, while de Vries can only manage 13th (18.335).
Quickest in the final sector, Verstappen improves to 17.056.
Again Albon goes quickest in S2, but subsequently pits.
Magnussen goes 12th, while Hulkenberg goes third but is demoted when Sainz posts a 17.349.
Hamilton goes sixth, while Norris can only manage 13th, which means Albon makes it through to Q3.
"Traffic, argh," wails Ocon.
On the pit-wall Zak Brown shakes his head in disappointment.
Quickest is Verstappen, ahead of Alonso, Sainz, Leclerc, Hulkenberg, Russell, Hamilton, Gasly, Stroll and Albon.
We lose Ocon, Tsunoda, Norris, Magnussen and de Vries.
Check out our Saturday gallery from Melbourne here.