Ahead of today's all-important qualifying session - and like Monaco, grid position is absolutely vital here - the air temperature is 32 degrees C, whilst the track temperature is 54 degrees. It is hot. Sunny and hot.

As in yesterday's two sessions, Lewis Hamilton was quickest however, following overnight changes teammate Nico Rosberg was able to close the gap indeed, the German was just 0.098s off the pace, setting us up nicely for this afternoon.

After a difficult day yesterday, Sebastian Vettel, never a winner here, had an altogether better morning, though his teammate suffered a "dramatic water leak" which left him with option tyre running earlier. Indeed, there was concern as to whether the issue could be resolved before this afternoon's session.

Whilst the Red Bulls were third and fourth yesterday, this morning only Daniil Kvyat was able to show what the RB11 can do on a track that should be kind to the Austrian team in that it doesn't make great demands in terms of engine power.

Despite yesterday's dramas, Force India looked good, though Sergio Perez isn't entirely happy with his car's set up.

With the track likely to suit Red Bull, Toro Rosso should also perform well, a fact confirmed by Carlos Sainz and Max Verstappen finishing fifth and seventh earlier.

The McLarens are looking better thus far this weekend, Fernando Alonso finishing ahead of the Lotus duo.

The one team that has yet to show what it is capable of here is Williams, fresh from its dramatic outing at Silverstone. Like many teams, the Grove outfit used yesterday to try new parts, Valtteri Bottas running a new front wing which the team may or may not run on Sunday.

The Saubers are both over 3s off the pace whilst the Manors are 5s adrift of the Mercedes duo.

Tyres this weekend are medium and soft, the gap between the two around 1.8s.

Based on hat we've seen thus far, in terms of different drivers and teams popping into the Top Ten, not to mention set-up problems and offs, this could be an intriguing session, particularly Q1.

Unusual to see a Mercedes out so early, eager beaver heads down the pitlane and is first to take to the track. Then again, following his drama at the end of FP3 - when he stalled the car - this might merely be an installation lap for systems checking purposes.

As more cars pour on to the track the German continues on his way, told that the reference time is 24.9. He responds with a 25.262 after a very scruffy lap, running over the kerbs in Turns 2,3 and 5. Teammate Hamilton, on the other hand, posts 24.293.

No sooner has Verstappen gone third (25.654) than Hulkenberg and then Bottas (25.372) go quicker.

Everyone bar the Manors on track.

Vettel goes second (24.901) and Ricciardo fourth (25.358) as Rosberg looks set to improve after a cooling down lap. He posts 24.905 which is only good enough for third.

All these times are on the medium rubber, the McLarens, Manors and Saubers already on the softer rubber.

On that softer rubber Button goes fourth (25.160) and Ericsson ninth (25.501) which cause a re-think further along the pitlane.

Rosberg runs wide in T4 after complaining about the balance of his car. "There's something wrong," he complains, "I've got so much oversteer".

Ricciardo goes second (24.631), Hamilton having upped the ante with a 24.213.

Alonso is the highest placed option runner, the Spaniard in sixth on 25.032. moments later however, Button improves to third (24.803).

A massive slide for Grosjean in T5 just moments after his teammate ran wide in T1.

Raikkonen is warned that the wind has picked up and is moving about.

With just under five minutes remaining, more and more drivers return to the track, all on options.

Bottas goes quickest with a 23.649 which may just cause Mercedes to re-think its strategy in terms of Hamilton. Rosberg is already back out on the softer rubber.

As Grosjean looks to get off the bottom of the timesheet, Hulkenberg goes second (24.115) only to be demoted by Kvyat who goes quickest with a 23.587.

As Rosberg posts 22.979 - the quickest time of the weekend - Hamilton leaves his garage on the softer rubber. The bluff has been called.

As Grosjean posts 24.242 to go eleventh, Alonso joins the Saubers and Manors in the drop zone. Button is hovering, along with Sainz and Perez. This could be tight.

A 24.563 sees Alonso improve to fourteenth as Rosberg continues to complain about balance.

Hamilton re-takes the top spot with a 22.890, whilst Button can only make sixteenth (24.739). "We didn't get deployment, we didn't get deployment ion the pit straight," he moans, referring to his ERS.