Ahead of today's second session the air temperature is 26.8 degrees C, while the track temperature is 42.6 degrees. While the threat of rain has eased, it remains quite windy.

Max Verstappen set the pace earlier, the Dutchman out-pacing Carlos Sainz, Fernando Alonso, Sergio Perez and Charles Leclerc.

As a reminder, in terms of upgrades Mercedes has a revised rear suspension and floor edge cut-out, Ferrari a new rear wing flap and beam wing. McLaren has an upgraded rear wing assembly and floor stay, while Alpine has a new beam wing and Aston Martin a new rear wing flap.

Following all the hoo-ha regarding the plan to introduce a metric aimed at reducing porpoising, the FIA has now confirmed that this will not happen this weekend. Instead, data will be collected from the teams with the aim of implementing the metric at Silverstone in two weeks.

In its efforts to resolve the problem, Mercedes ran its drivers with different floors earlier, Hamilton's featuring a new floor with a significant - Red Bull style - cut-out and Russell's without.

The lights go green and Bottas leads the way, followed by Zhou, Vettel, Stroll and Ocon.

However, in the Mercedes garage both cars are still being worked on as the German team carries out a number of changes.

Already, Vettel is under investigation for an unsafe release, the German almost collecting Magnussen.

In no time at all there are 15 drivers on track, most are on mediums though Magnussen is on hards while Ocon, Alonso and Leclerc are on softs.

Verstappen goes quickest (15.618), ahead of Perez, Ocon, Sainz and Gasly.

Ricciardo goes third with a 16.796, only to be demoted when Leclerc stops the clock at 15.675 to go second.

Previously, told to do two burnouts as he headed out, Leclerc simply replied "What's going on, I cannot do burnouts!"

Verstappen and Leclerc both improve, the Dutchman to 14.792 and the Ferrari driver to 15.288. However, as Alonso goes third, the Spaniard and Leclerc are on softs whilst the Dutchman is on mediums.

All bar the Mercedes pair and Vettel are on track.

Twelve minutes in and the Mercedes pair head out.

Alonso improves to second with a 15.125, ahead of Leclerc, Sainz, Perez and Norris.

"Bouncing and bottoming is worse than FP1," says Sainz.

Russell's first lap sees the Briton go ninth (16.029) on mediums, as he reports "massive hopping in Turn 9".

Hamilton's first lap sees the seven-time champ go sixth (15.852).

"Bouncing is very bad, guys," says Sainz... his claim borne out by the TV replay.

Leclerc improves with a 14.830.

Gasly is under investigation for failing to follow the race director's instructions in terms of not driving to the left of the bollard after going off at Turn 14.

Bottas has only completed 2 laps - and not posted a time - as mechanics continue to work on his car. He waits patiently with his helmet ion suggesting he'll be out soon.

Indeed, the Finn heads out, but completes just one lap before reporting an issue. "There's still something weird, with the anti-stall," he reports.

The VSC is deployed when a tin can appears in the middle of the track.

On softs, Vettel goes fifth with a 15.299, while Verstappen, now on softs, raises the bar with a 14.127.

Perez can only manage fifth (15.167), over a second off his teammate's pace.

Christian Horner puts the difference between his two drivers down to the fact that Verstappen is happier with the balance of his car.

The stewards have noted another incident, this time at the pit exit involving Sainz and Vettel.

A 14.208 sees Leclerc close to within 0.081s of Verstappen.

Bottas remains in his garage, the Finn with just 3 laps under his belt.

Gasly improves to sixth with a 14.879 while Vettel posts a 14.442 to go fourth.

Ricciardo is told that he's losing out due to his minimum speed in Turn 3.

No doubt looking ahead to Sunday, Verstappen switches to the mediums. Vettel, Gasly and Russell subsequently follow suit.

Verstappen is told that heavy rain is expected after the end of the session but that there could be "a few drops" beforehand.

Like Gasly, Vettel is now under investigation for failing to follow the race director's instructions vis-à-vis the bollard at Turn 14.

Alonso switches to hards, as do Ocon and Magnussen.

With 9 minutes remaining, all bar Bottas are on track.

"This car is undriveable," says Hamilton as he heads into the pits, the Briton currently 13th while his teammate is 7th.

Leclerc, who has only run the softs in this session, spends a couple of laps running close behind Ricciardo, suggesting to some that Ferrari is preparing for an engine penalty for Sunday.

The session ends. Verstappen is quickest, ahead of Leclerc, Sainz, Vettel, Alonso, Gasly, Russell, Norris, Ricciardo and Ocon.

Perez is eleventh, ahead of Stroll, Hamilton, Magnussen, Schumacher, Zhou, Tsunoda, Albon, Latifi and Bottas.

Early day, but of the big guns, the only driver who looks likely to be getting a good night's sleep tonight is Verstappen.

While Leclerc has pace he looks set to be taking on another engine and therefore a grid penalty, while teammate Sainz, like the Mercedes pair is hampered by bouncing.

Then there's Perez who simply isn't happy with the balance of his car.

Adding to the fun is the fact that veterans Vettel and Alonso are fourth and fifth.

Check out our Friday gallery from Montreal here.