Ahead of today's opening session the air temperature is 25 degrees C, while the track temperature is 36 degrees - however, the mainstream media will no doubt be telling you that it is actually 45 and 66 degrees, with the tyres - and fans in the stands alike - in danger of melting.

Currently, fairly bright there is a lot of cloud around with the threat of rain both today and tomorrow. Indeed, there is an 80% chance of rain over the next hour.

In terms of upgrades, Red Bull has a new Front Corner, Rear Corner, Sidepod Inlet, Coke/Engine Cover and Floor Body, while Ferrari has a new Front Wing and Mercedes a new Front Wing, Front Suspension and Rear Wing.

Alpine has a new Front Wing, while Aston Martin has a new Coke/Engine Cover, Haas a new Floor Body and AlphaTauri a new Front Wing, Nose, Floor Body and Rear Wing.

There are no updates for McLaren, Alfa Romeo or Williams.

The ATA - Alternative Tyre Allocation - being used tomorrow in qualifying, which will see all three compounds used, means we should see all three in action today.

Something else we will see in action today is Daniel Ricciardo, who, you may have heard, replaces Nyck de Vries in the AlphaTauri.

The lights go green and Russell leads the way, followed by Albon, Ricciardo, Tsunoda and Magnussen.

As more drivers emerge it is mostly softs and mediums that are in use. Soon, all bar Hamilton are on track - the Briton an eight-time winner here.

"Why am I losing so much energy," asks Zhou, who is immediately told to box.

Oh dear, Perez is off and in the barrier at Turn 4.

"I cannot believe this," he says as the session is red-flagged.

Replay shows him dipping his left-front on the grass at the exit of the corner and simply losing the car which spins into the barriers.

Helmut Marko is not impressed, especially as the Mexican was running the upgrades.

The stricken Red Bull is lifted into the air, a marshal carrying the front wing.

The session resumes with 48 minutes remaining.

Magnussen leads the way, followed by Albon, Ricciardo, Piastri and Hamilton.

Ricciardo is warned of light rain on the pit straight. In the stands, fans are raising umbrellas and donning ponchos.

Leclerc and Hamilton both warn that it is raining.

Indeed, as it intensifies, Bottas spins off at Turn 12. "It's undriveable," he reports , as his fellow drivers pit.

After several minutes of inactivity, Hamilton heads out on Inters. He pits after just one lap.

Shortly after, Ocon heads out, the Frenchman also sporting the green-banded rubber.

As he too pits after just one lap, Sainz heads out, followed by Albon.

"It's obviously frustrating to have had that off," Christian Horner tells Sky Sports. "We haven't got the car back yet, but hopefully the damage is contained to that front right corner and will be repairable before the second session.

"It was unfortunate," he adds, "he just put a wheel on the grass. He won't have lost too much this session as people aren't putting many laps in.

"It was just a mistake, you could hear the frustration in his voice. It is what it is."

Leclerc is next to dip his toes in the water, so to speak.

Hamilton reports that half of the track is dry and it is therefore damaging his tyres. Too wet for slicks, too dry for Inters.

Piastri, Magnussen and Norris head out... at which point the heavens open.

Norris is told that the rain is too heavy to continue. His disagrees, but nonetheless opts to pit.

With 23 minutes of the session remaining, we've yet to see a time posted.

As Bottas heads out, Perez's car arrives back in the pitlane.

"It's OK, low grip, but for now it's driveable," reports Bottas.

Albon, Ricciardo and Sargeant head out as Bottas posts a 47.787.

Verstappen and Sainz head down the pitlane as Albon posts a 47.407.

Another red flag, this time as Sainz goes off at Turn 3. The car is beached "I'm stuck," reports the Spaniard, his car having gone off after losing the rear, clouting the barrier and bouncing back leaving the car at an angle to the track, half on the grass and half just inches above the tarmac.

Sargeant had just gone quickest (of three) with a 46.838.

As Sainz arrives back in the pits, the session resumes with 11 minutes remaining.

Stroll, Hulkenberg and Alonso head out, followed by Russell.

Hulkenberg posts a 44.722, but Alonso responds with a 43.277.

Bottas improves to second but is demoted when Leclerc posts a 42.909. Magnussen is third, ahead of Bottas, Hulkenberg, Norris and Russell.

A 40.687 sees Alonso go top, ahead of Stroll, Leclerc, Russell and Norris.

Meanwhile, Hamilton is out of his car, the Briton one of six drivers that hasn't posted a time.

Sargeant goes off at Turn 4, as Tsunoda has a moment at Turn 5 and Norris goes off at Turn 3.

Russell goes quickest with a 40.444 but is leapfrogged by Piastri (39.906).

Russell retakes the top spot with a 39.652 as Stroll goes third. However, Piastri responds with a 39.154.

The session ends. Russell is quickest, ahead of Piastri, Stroll, Norris, Alonso, Bottas, Leclerc, Zhou, Sargeant, Hulkenberg, Magnussen, Tsunoda and Albon.

While Ricciardo, Sainz, Perez, Ocon, Gasly, Verstappen and Hamilton all failed to post times.

Check out our Friday gallery from the Hungaroring here.