Ahead of today's second practice session, the air temperature is 21.2 degrees C, while the track temperature is 36.1 degrees.
At the top of the timesheets in FP1 it was pretty much business as usual, with Valtteri Bottas heading Lewis Hamilton and Max Verstappen.
However, session was notable for the sheer number of times drivers had their times deleted for exceeding the track limits, particularly in Turns 1 and 4.
Courtesy of a new track surface, unfamiliarity with the track and the tyres choice - the hardest in the range - drivers struggled to stay on the black stuff, and though there were a few spins nobody ended up in the gravel.
On the subject of tyres, for the first thirty minutes of this session the teams will be 'blind testing' a number of compounds for Pirelli as the Italian manufacturer looks ahead to 2021.
The lights go green and the Alfa pair lead the way, followed by Ocon, Albon, Russell and Sainz. All are on prototypes, plain black tyres that make identification impossible.
Consequently, the times posted over the next thirty minutes are immaterial.
Magnussen and Sainz playing silly buggers in Turn 1, the Spaniard forced to go wide. Shortly after the McLaren driver spins at Turn 13.
Despite the 'meaninglessness' of the times - certainly as far as this weekend is concerned - Hamilton goes quickest, ahead of Leclerc, Giovinazzi, Raikkonen and Perez.
With all twenty drivers on track, it is understandable when Leclerc complains about the amount of traffic.
As in FP1, drivers continue to fall foul of the track limits and have their times deleted as a result.
Perez spins at Turn 3, shortly after Grosjean took a rough, bumpy ride through the gravel at Turn 11.
"This is pointless, we're just wasting our time in traffic," complains Vettel. "It's completely silly."
Bottas is quickest, ahead of Verstappen, Hamilton, Leclerc and Sainz.
Having received no response to his warning over vibrations, Hamilton asks: "Are you there?" Classic.
The world champion is subsequently told to pit if he is unhappy with the vibration. And pit he does.
Indeed, pretty much everyone else also pits, even though there is around 8 minutes of the allotted test timer remaining.
It's understood that there were over 60 instances of drivers having their times deleted in FP1, and by the looks of it FP2 could well produce similar numbers.
Told he has exceeded the limits at Turn 1 again, Grosjean responds: "F***, they need to change that, it's impossible to see. I really tried on my last lap not to do it, it's impossible."
The tyre test comes to an end, leaving an hour of further preparation for the weekend ahead.
Gasly, Albon, Vettel and Russell waste no time in switching to mediums, all happy to enjoy a comparatively clear track.
Gasly immediately goes quickest in S1, while Russell goes quickest in S2.
Russell goes quickest with a 20.822, but Gasly responds with a 20.037. The best time on the prototypes was Verstappen's 21.575.
Gasly improves to 19.197 but is subsequently leapfrogged by Vettel (19.175).
As the Mercedes pair heads out Leclerc goes third with a 19.229. The Black Arrows are the first to run the softs this weekend.
In quick succession Vettel and Kvyat spin at Turns 14 and 13, respectively.
Verstappen (mediums) goes quickest with an 19.033 as Hamilton loses precious time behind a struggling Kvyat.
No sooner has Leclerc gone top (18.838), than Bottas posts 17.940.
"There's no grip in these tyres," complains Hamilton, the Briton having completed two warm-up laps.
Gasly parks by the side of the track, flames leaping from the back of the AlphaTauri.
As marshals with extinguishers run to the car - from which Gasly soon extricated himself - the session is red-flagged.
With the session still under red, this, combined with the half hour lost to the tyre test, is really compromising the teams' preparations.
The session is given the green light with just under thirty minutes remaining. Bottas heads the queue at the end of the pitlane, with teammate Hamilton tucked in behind.
The Red Bulls head out together also, Verstappen wasting no time in passing his young teammate.
As more and more drivers emerge, all are sporting the red softs.
Hamilton improves to sixth (19.308), as Verstappen aborts his lap.
"The tyres were not ready," complains the Dutchman.
Moments later, the Red Bull is in the gravel after tangling with Stroll in Turn 1.
The session is red flagged again.
Verstappen appeared to be ready to pass the Canadian on the pit straight, but as they went into the corner the Racing Point driver pulled across on the Dutchman. While the Red Bull driver is able to get back to the pits, the Point is stranded in the gravel.
Surely one for the stewards. Indeed, they are investigating.
Otmar Szafnauer says that Stroll was running two consecutive hot laps and claims that Verstappen "shouldn't have been there".
"What the f*** is wrong with him," demands Verstappen on the radio replay, with a few other expletives thrown in.
Stroll, on the other hand, is far more sanguine about the incident.
Another replay reveals that before the incident Stroll had passed Verstappen, who must have therefore been aware that the Canadian was on a hot lap.
The session resumes with just 8 minutes remaining.
Sainz heads the queue at the end of the pitlane, ahead of Albon and Hamilton.
Russell complains that only one of his earphones is working and it is very distracting.
Despite so little time being available, drivers continue to have their times deleted.
As the clock ticks down, all bar Gasly and Stroll are on track.
Understandably, drivers complain about traffic. Ricciardo, who encounters a slow Latifi, is forced to abort his lap.
Next time around the Australian improves to 12th with a 19.987, as teammate Ocon posts 19.496 to go 9th.
Sainz goes fourth (19.113), as Norris and Kvyat look set to improve.
Norris goes third with an 18.743.
The session ends.
Bottas is quickest, ahead of Verstappen, Norris, Leclerc, Sainz, Vettel, Gasly, Hamilton, Ocon and Albon.
Russell is eleventh, ahead of Perez, Ricciardo, Latifi, Raikkonen, Magnussen, Kvyat, Grosjean, Stroll and Giovinazzi.
Check out our Friday gallery from Portimao, here.