Ahead of today's sole free practice session the air temperature is 16.9 degrees C, while the track temperature is 23.5 degrees. It is bright and cool with quite a lot of cloud. There is a 20% chance of rain according to Race Control.
While the Ferraris were third and fourth, both drivers struggled with graining, and other than this fear that Mercedes has more in store.
McLaren and Toro Rosso looked strong, while Renault struggled in the afternoon, Daniel Ricciardo subsequently changing his engine and chassis overnight. Kimi Raikkonen, like Ricciardo, stopped on track with an engine issue, and like the Australian has changed units overnight after missing much of FP2.
The big factor yesterday, other than the new track surface, which according to most remains bumpy, was the wind, with even the best of them struggling to remain on the black stuff, particularly in the Maggots/Becketts complex. Thankfully, it is a little less blowy today.
The lights go green and Norris leads the way, followed by Hulkenberg, Albon and Grosjean. A mixture of all three compounds, Hulkenberg on the hards.
Russell (mediums) posts the first time of the day, the Williams posting an exploratory 37.974. He subsequently improves with a far more sensible 31.810.
The Haas pair are already on softs as the American outfit seeks to get to the bottom of its tyre issues.
Ten minutes in and with just one time on the board, light rain begins to fall.
After several minutes of inactivity, Leclerc and Ricciardo head out on Inters.
Ricciardo reports a "light film of water" on the track, and while feeling it is too damp for slicks he also believes it isn't wet enough for the Inters.
Russell, Hamilton and Bottas also head out on the green-banded rubber.
Bottas is told that the combination of the new tarmac and rain will make it slippers (duh!) and that it will be difficult getting the tyres to work.
"Get a balance check, in case we get anything like this in qualifying," Hamilton is told.
Bottas posts 35.423 and Kubica 42.800 as Vettel heads out on Inters.
Just after the half hour, with those three times the only times on the board, Hamilton heads out on softs, much to the delight of the crowd. Hulkenberg is also on the red-banded rubber.
Hulkenberg posts 29.711, while Hamilton subsequently crosses the line at 28.988.
Cue rivals hurriedly switch to the slick rubber.
Leclerc posts 27.446 on the softs as teammate Vettel heads out.
Bottas posts 27.524, with Vettel posting 27.840 moments later.
"I hear a strange noise from the turbo," reports Gasly.
As the rear of the Red Bull brushed the tarmac, the sparks thrown out make it appear as though Gasly is driving on a sea of fire.
Hamilton retakes the top spot with a 26.746, as Leclerc improves to 26.925.
Verstappen is the last driver to post a time, the Spielberg winner stopping the clock at 27.269 to go 5th.
Bottas raises the bar with a 26.458, which is quicker than what we saw yesterday.
Behind the big three (or six), it's: Albon, Kvyat, Hulkenberg, Norris, Ricciardo and Sainz.
Hamilton improves to 26.338 as Verstappen goes third with a 26.654.
A 26.965 sees Ricciardo go sixth, ahead of Gasly. However, the Frenchman subsequently improves to fourth with a 26.689.
With 11 minutes remaining, the Ferrari pair head out on fresh softs for their qualifying sims. Vettel posts PBs in the first two sectors, while Leclerc goes quickest in the first.
At the line Vettel posts 26.700 to go fifth, while Leclerc goes quickest with a 25.905.
Now the Mercedes pair head out on fresh rubber, as Leclerc goes quicker again in S1.
Woah! Bottas is lucky not to come to grief, after Kvyat moves across on him as he attempts to pass Leclerc at T8 (Woodcote).
Meanwhile, Vettel goes second with a 25.931.
Hamilton posts 26.131, as he remains 0.226s off Leclerc's pace.
A big, big wobble for Verstappen in T7 as he appears to apply the power too early.
Ricciardo remains seventh, ahead of his Renault teammate, with Sainz and Kvyat rounding out the top ten.
Hamilton told that the Ferrari pair's times are probably down to "going up with the PU".
More fun and games as Magnussen moves across on Sainz after the Spaniard accidentally impeded the Dane.
"The car's not got a lot more to give," warns Hamilton.
Verstappen splits the Mercedes pair with a 26.440.
At the death, the Dutchman is demoted when teammate Gasly bangs in a 26.118, meaning that the Frenchman has been quicker in all three sessions.
A late improvement for Norris sees the Briton leapfrog the Renault pair to claim 'best of the rest'.
The session ends, and in what might well be called a 'turn up for the books', Leclerc is quickest, ahead of Vettel, Hamilton, Gasly, Verstappen, Bottas, Norris, Hulkenberg, Ricciardo and Albon.
Giovinazzi is eleventh, ahead of Sainz, Kvyat, Grosjean, Magnussen, Raikkonen, Stroll, Perez, Russell and Kubica.