Ahead of today's free practice session, the air temperature is 25.9 degrees C, while the track temperature is 37.1 degrees. Like yesterday it is bright and sunny.

As ever, Mercedes set the pace on Friday, Valtteri Bottas quickest in the morning and teammate, Lewis Hamilton in the afternoon.

However, based on yesterday's evidence, Red Bull is likely to be under pressure from AlphaTauri and McLaren, while Renault has yet to show its hand.

The FIA's ongoing crackdown on track limit violations saw many times deleted yesterday, and drivers will need to be extremely cautious this afternoon.

As the 'grouping' silliness which sees drivers running as a pack rather than seeking a gap, reaches new heights, the FIA has acted.

Aware that the practice is an accident waiting to happen - Lewis Hamilton describing it as a "nightmare" the FIA is setting a maximum time that drivers will need to adhere to in this session and again this afternoon.

Having seen the penalties meted out in the support sessions earlier, the F1 drivers would be well advised to take heed.

The lights go green and Giovinazzi is straight of the box, followed by Raikkonen, Grosjean and Norris. Magnussen and Gasly also head out, but moments later all are back in their garages.

And with that... silence descends.

Ten minutes later, a Renault fires up and Sainz heads down the pitlane. The Spaniard is on softs.

Sainz posts 21.875 but there is no rush to join him.

Finally, Raikkonen heads out again, as do the Haas pair and then the Ferraris. A fair mixture of softs and mediums.

In moments all twenty drivers are on track.

Raikkonen posts 22.173 and Grosjean 22.552, while Vettel posts 22.135 and Leclerc 21.766.

A 21.441 sees Ricciardo go top, as Kvyat goes fifth and Ocon 6th.

Hamilton goes top with a 20.658, with Bottas posting 20.774 moments later.

"Are you sure everyone is respecting the delta," asks Leclerc as the cars once again are visibly bunching.

Verstappen goes seventh (21.548) and Albon 13th (22.270).

Gasly goes third with a 21.275 as Ricciardo looks set to improve. The Australian posts 21.314 but actually begins to slip down the order as others improve.

Ocon goes third (20.856), ahead of Verstappen, Perez, Gasly, Kvyat, Albon, Stroll and Ricciardo.

Having posted their times on mediums, the Mercedes pair now head out on softs.

Bottas immediately improves to 20.622, while Russell goes 14th with a 22.017.

Albon has his time (21.168) deleted.

PBs in all three sectors, see Verstappen go top (20.456) on the mediums.

"There is a problem, there is a problem," reports Grosjean, "that's the third one this weekend."

Leclerc has his latest time (21.883) deleted.

Albon improves to fifth with a 20.952, 0.496s down on his teammate. However, his time is subsequently deleted.

With 23:00 remaining, it's: Verstappen, Bottas, Hamilton, Ocon, Perez, Kvyat, Gasly, Stroll, Ricciardo and Norris.

At which point the circuit once again falls silent. The calm before the storm, as it were, as we await the qualifying sims which should give a clearer idea of the pecking order.

The Black Arrows are first out, Bottas leading the way. Unlike their rivals, they are not running together, as this pair have no need for tows.

Bottas goes quickest in S2, finally crossing the line at 20.89 to go top, but his time is likely to be deleted. Hamilton subsequently aborts his lap, as his teammate's time stands.

A PB in S2 for Hamilton who stops the clock at 20.439 to go second.

The pair have the track to themselves... until the Ferrari pair head out. In the moments that follow, more drivers head out.

Vettel improves to 10th (21.263) and Leclerc 5th (20.917), but ion no time at all both begin to slip down the timesheets as their rivals improve also.

Ricciardo goes third (20.419), but is demoted when Norris posts 20.412.

As Albon goes sixth, Ricciardo pulls to the side of the track. "I have an issue," he reports.

Out come the yellows... and then the red.

With 08:04 remaining, that will have compromised everyone's programmes.

As the Renault is removed, all remaining drivers wait for the all-clear, and with 03:15 remaining it is given. Which, of course, means they all head out together.

The traffic jam moves along the straight into the Parabolica as the drivers have time for one flyer.

No purples but a good smattering of greens.

Sainz goes second (20.318), while Albon has his 20.675 deleted.

Stroll goes ninth and Perez tenth, while Raikkonen improves to 17th.

Phew! Replay shows Hamilton heading through the field at break-next speed as they head into the Parabolica. Two cars are side-by-side and the Mercedes driver has to take to the grass to avoid them.

That, in our humble opinion, was totally irresponsible of the world champion, and what appeared to be Grosjean - we could be wrong - who was overtaking a rival at the time.

Bottas is quickest, ahead of Sainz, Norris, Ricciardo, Hamilton, Verstappen, Albon, Ocon, Stroll and Perez.

Leclerc is eleventh, ahead of Gasly, Kvyat, Grosjean, Vettel, Magnussen, Raikkonen, Russell, Latifi and Giovinazzi.

Check out our Saturday gallery from Monza, here.