Ahead of today's sole practice session the air temperature is 19 degrees C, while the track temperature is 37.8 degrees C. It remains bright and sunny.

While today, like yesterday, it is warm, tomorrow is expected to be even warmer, which is already causing concern within the teams in terms of tyre deg.

Though Charles Leclerc topped the timesheets in the second session, Mercedes, once again, appear to have the edge in terms of race pace, enjoying a 0.8s advantage over Ferrari, and is only slightly off Ferrari's pace over a single lap on the softs.

Of course, with Lewis Hamilton and Max Verstappen sidelined after clouting the walls we don't have the complete picture, but it's fair to say that the Silver Arrows are looking might strong.

Though Ferrari is strongest in the final sector, courtesy of its sheer grunt, the corners in the opening two sectors play into Mercedes hands.

We saw yesterday that drivers were struggling, with the rears particularly susceptible to overheating, warmer temperatures tomorrow will make life extremely difficult and there is already talk of two pit stops. Indeed, there is talk of queues in the pitlane just a few laps into the race as drivers seek to shed their softs or mediums.

With Carlos Sainz an impressive fourth, McLaren is looking strong here, and could even eclipse Red Bull, with Renault and Toro Rosso also looking strong on race pace.

The lights go green and Norris leads the way, followed by Magnussen, who looked strong yesterday, unlike his teammate who was in full Monsieur Moany mode.

Grosjean and Albon are next out, a fair mixture of softs and mediums.

While Kubica posts a time (1:17.718), six minutes into the session only eight drivers have appeared, none of the big guns showing signs of going out any time soon.

As Kubica improves to 16.732, Hamilton is strapped in his car.

As was the case yesterday, the track is fairly dusty and will need a period of rubbering in, though it will need more than Kubica to do this.

After several minutes of total inactivity, Magnussen heads out again. He is followed by Kvyat and Gasly.

Magnussen posts 15.129, but moments later Gasly stops the clock at 14.280. Both are on the mediums.

A 13.569 sees Raikkonen go top as Vettel and Leclerc are the first of the big guns to emerge, no offence to Gasly.

Leclerc locks-up twice on his fast lap, finally crossing the line at 12.614, with Vettel posting 12.478 moments later. Both are on the softs.

Hamilton goes third with a 12.735, the Briton also on the red-banded rubber.

Stroll grinds to a halt as he enters the pitlane, and as smoke billows from the rear of the car he is advised that it's a hydraulic leak.

Bottas leapfrogs his teammate with a 12.683, the Finn just 0.205s off Vettel's pace.

Leclerc raises the bar with an 11.596, as Albon goes sixth, ahead of Kvyat, Raikkonen, and Norris.

Hamilton improves with a 12.176, as Bottas and Vettel trade fastest sectors. Vettel crosses the line at 11.706, while Bottas has a poor final sector and remains fourth.

Verstappen goes fifth with a 12.551 on the mediums, just ahead of his Red Bull teammate.

In the Ferrari garage, the team is experiencing the same issue as Haas faced yesterday with the cars ripping up the floor paint.

Quickest in S1, where he shouldn't be, Vettel goes quickest with an 11.557.

Norris takes a punishing ride over the kerbs at Turn 13. The stewards subsequently announce that they will investigate as he didn't rejoin the track in the correct way.

Traffic is an issue, and as drivers back up in order create a gap, they merely add to the problem.

As he seeks to improve on fourteen, Grosjean kisses the Wall of Champions with his right-rear.

Bottas continues to improve his time but remains fourth.

Leclerc complains that every time he leaves the pits he has tarmac (paint?) on his tyres. "We need to be careful," he warns.

Verstappen finally makes the switch to softs.

While Stroll doesn't look like coming out any time soon, Perez goes seventh, ahead of Kvyat, Norris, Albon, Hulkenberg and Ricciardo.

Raikkonen complains that there's an "animal" (groundhog) "running around before turn 6", though he's not sure what it's called.

Bottas has the track to himself as he begins his qualifying sim on a brand new set of softs. He is quickest in the first two sectors and again in the third, crossing the line at 11.531.

Nonetheless, he is 13 km/h slower than the Ferrari through the speed-trap.

Leclerc can only manage a PB in S1 but strong final sectors see him raise the bar with an 11.058, just moments after Vettel had posted 11.478.

Hamilton aborts his first flying lap, next time around however, a PB is S1 is followed by a purple in S2 and another PB in S3, crossing the line at 11.236.

Looking set to improve, a mistake sees Vettel lock-up and subsequently abort the lap.

Leclerc improves again, the Monegasque stopping the clock at 10.982.

Meanwhile, Norris has gone fifth (12.154) and Albon seventh, splitting the Red Bulls.

As Verstappen posts a PB in S1, Vettel goes quickest. Both post PBs in S2, the German going quickest overall - on his third flying lap - with a 10.843, while Verstappen goes fifth with an 11.842.

A 12.175 sees Perez go seventh.

PBs in all three sectors see Gasly go sixth, 0.095s off his teammate's pace.

Magnussen can only manage 13th (12.656), while teammate Grosjean is still down in 17th.

Ricciardo goes seventh with a 12.045, as teammate Hulkenberg seeks to improve on 11th.

The session ends. Vettel is quickest, ahead of Leclerc, Hamilton, Bottas, Verstappen, Gasly, Ricciardo, Norris, Perez and Kvyat.

Hulkenberg is eleventh, ahead of Magnussen, Sainz, Albon, Giovinazzi, Raikkonen, Grosjean, Russell, Kubica and Stroll.

Check out our Saturday gallery from Montreal, here.