Ahead of today's opening session the air temperature is 32 degrees C, while the track temperature is 50 degrees. It is gloriously bright, hot and beautiful, we're in Monza.
Being the Temple of Speed there are a lot of circuit specific upgrades. Red Bull has a new Front Wing and Rear Wing, while Mercedes has a new Rear Wing and Ferrari a new Front Wing, Nose, Mirror, Floor Fences, Floor Body, Floor Edge, Diffuser, Coke/Engine Cover and Rear Wing.
McLaren has a new Front Corner, Front Wing and Coke/Engine Cover, while Aston Martin has a new Front Wing, Beam Wing and Rear Wing, and Alpine a new Front Wing.
Williams has a new Front Wing and Rear Wing, RB a new Front Wing, Floor Body, Rear Wing, Beam Wing, Halo and Mirrors, while Stake has a new Front Wing, Floor Body, Diffuser and Rear Wing and Haas a new Front Wing and Front Suspension.
There are two main focuses of attention this morning, Franco Colapinto who replaces Logan Sargeant at Williams and Kimi Antonelli who may well partner George Russell at Mercedes next season.
Though the layout remains the same, there have been big changes since F1 last visited, most notably the entire track has been resurfaced.
Understandably, there is a lot of media outside Antonelli's garage, ahead of the Italian's FP1 debut.
The lights go green and Alonso leads the way, followed by Stroll, Gasly, Hulkenberg and Tsunoda. All three compounds are in use as the team - and Pirelli -seek to extract as much data as possible.
Sainz goes quickest with a 26.382 but is immediately demoted by Hamilton and then Antonelli, who crosses the line at 23.955.
Early mistakes from Verstappen and Leclerc at the chicane as Norris goes second with a 24.371.
Tsunoda goes fourth on the hards as Bottas goes second on mediums.
Piastri pits to remove a ginormous sensor removed from the car.
Oh dear. Antonelli has crashed in the Parabolica, after the rear end got loose. The youngster is OK, which is more than can be said of his car.
As the session is red-flagged Toto Wolff looks none too happy.
"Sorry," says the youngster. "Kimi, all good, all good Kimi," replies Wolff.
As it stands, Hamilton is quickest (23.350), ahead of Norris, Bottas, Antonelli, Albon and Gasly.
Meanwhile, Sainz and Magnussen are to be investigated for impeding.
New power units for the Mercedes, McLaren, Aston Martin, Stake and Haas drivers along with Colapinto.
"It changes nothing," says Mercedes chief communications office, Bradley Lord of Antonelli, "it is all part of the learning curve for a young driver."
The session resumes with 37 minutes remaining.
Verstappen is first out, followed by Stroll, Ricciardo, Alonso and Perez.
Verstappen (softs) goes quickest with a 23.088, despite not being quickest in any of the three sectors.
Moments later, Albon (medium) goes quickest with a 22.664 only to be demoted by Bottas (softs) who stops the clock at 22.416.
Norris goes third and Hamilton fourth while Piastri improves to tenth with a 23.940.
"Vibration, front tyres," reports Hamilton, despite which he goes quickest with a 22.214 on the softs.
A 22.157 sees Bottas go top, 0.087s up on his former teammate. Meanwhile, his current teammate (Zhou) goes seventh with a 22.854.
A 22.880 sees Colapinto go ninth, while teammate Albon is currently third (22.220).
"Instability entry and exits and a bit too much understeer in some corners," reports Albon.
Much to the delight of the crowd, Leclerc goes second with a 22.139, just 0.012s off Bottas' pace.
"Ooh, tricky one," admits Sainz after a major wobble in the Parabolica.
Having been cleared by the medics, Antonelli makes his way back to the Mercedes garage.
Magnussen goes tenth with a 22.572, the Dane, like the majority now, still on softs.
PBs in all three sectors see Alonso go ninth.
Leclerc goes quickest and his teammate third, but both are demoted when Verstappen bangs in a 21.676.
All three compounds still in use, though Tsunoda is the only driver persisting with the hards.
Bottas reports graining, the Finn still fifth.
Oversteer sees Colapinto run wide at Parabolica, ass Ocon spins on the Sausage kerb at Turn 1.
The session ends. Verstappen is quickest, ahead of Leclerc, Norris, Sainz, Bottas, Piastri, Hamilton, Albon, Perez and Alonso.
Magnussen is eleventh, ahead of Ricciardo, Tsunoda, Gasly, Zhou, Stroll, Colapinto, Ocon, Hulkenberg and Antonelli.
Check out our Frinday gallery from Monza here.
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