Ahead of today's opening practice session the air temperature is 25.5 degrees C, while the track temperature is 36.4 degrees. There is a 10% chance of rain.

Updates this weekend include a new front wing flap and beam wing for Mercedes, a new rear wing for Red Bull, as beam wing for Ferrari and front and rear wing flaps for McLaren.

Alpine has removed its beam wing gurney, while Aston Martin has new front and rear wing flaps and Williams has a new single element beam wing.

AlphaTauri, Alfa Romeo and Haas have brought no updates.

As expected, Yuki Tsunoda picks up a 10-place grid penalty having accumulated 5 reprimands this season. Lewis Hamilton is set to start from the back of the grid after taking on a new engine, while Valtteri Bottas and Max Verstappen are also looking likely to be penalised for taking on new power unit elements.

There are a couple of young drivers on duty this morning, Nyck de Vries at Aston Martin, where he replaces Sebastian Vettel, while Antonio Giovinazzi replaces Guanyu Zhou at Alfa Romeo.

Ahead of the session, there is a minute's silence following the death of Her Majesty, Queen Elizabeth II.

The lights go green and de Vries leads the way, followed by Magnussen, Sainz, Ocon, Tsunoda and Stroll.

With the threat of rain there are soon 17 drivers on track using all three compounds.

Of the first wave, Verstappen goes quickest (25.230), ahead of Perez, Ocon, Sainz and Magnussen.

As was the case at Baku, the upper element on the Red Bull's rear wing is oscillating, Perez subsequently told not to use DRS.

Perez improves with a 25.026 as Ricciardo goes third (25.386).

At which point the FIA confirms a 5-place grid penalty for Verstappen for taking on a new ICE. Tsunoda, Sainz and Perez will also take grid penalties.

We are likely to see Spa levels of grid changes come Sunday.

Verstappen posts a 23.449 as Ocon goes second (24.281), ahead of Perez, Albon, Alonso and Leclerc.

Alonso goes second with a 24.026, as Perez gets the first chicane wrong.

On softs, Tsunoda goes second with a 23.957. Verstappen and Alonso are on softs, while Ocon and Albon - in fourth and fifth - are on mediums.

Twenty-four minutes in and the AlphaTauri pair have the track to themselves.

They are subsequently joined by Albon, Leclerc, Stroll and Ricciardo, who are all on softs.

No sooner has Magnussen gone third on the softs (24.006), than Lecelrc stops the clock at 22.410.

Other than the yellow added to the Ferrari's livery for this weekend, the rear of Leclerc's car is smothered in yellow flo-vis.

Verstappen bolts on the softs but loses a heap of time in S3 as he encounters Norris. Prior to that he had been quickest in the first two sectors. "Unbelievable," says the world champion.

Russell goes third (22.990) on the softs, as Ocon, sporting a Michael Schumacher tribute helmet, goes fourth (23.075).

A 22.487 sees Sainz go second as Ricciardo, currently 9th, switches to mediums.

"The thig is just not stopping into Turn 1," reports Russell.

With Ferrari very much playing down hopes ahead of this weekend's race, let's not forget that over the years the Scuderia has often dominated on Friday and consequently helped sell tickets for the remaining days.

With all having run the softs, Bottas and Albon join Ricciardo in switching to mediums, while Stroll is on hards.

Hamilton goes fourth with a 22.831, ahead of Verstappen, Ocon, Alonso and Tsunoda.

"Oh my God," declares Russell, "I almost crashed into the back of Sainz, he just parked on the exit of Turn 5."

Not for the first time, Perez locks-up into Turn 1, the first chicane proving difficult for a number of drivers this morning.

Shortly after, de Vries is off and through the gravel.

The session ends. Leclerc is quickest, ahead of Sainz, Russell, Hamilton, Verstappen, Ocon, Alonso, Tsunoda, Bottas and Ricciardo.

Albon is eleventh, ahead of Zhou, Gasly, Perez, Stroll, Norris, Magnussen, Giovinazzi, De Vries and Latifi.

Check out our Friday gallery from Monza here.