Ahead of today's second session the air temperature is 19 degrees C, whilst the track temperature is 24 degrees. While the rain threatened during the closing stages of FP1 it wasn't until around forty-five minutes ago that the weather gods finally let rip, hitting the playground of the rich and (in)famous with a hailstorm of biblical proportions.
While the rain has now stopped, the track remains wet and there is the threat of further downpours to follow.
Lewis Hamilton was quickest this morning edging out teammate Nico Rosberg by just 0.032s. Daniel Ricciardo was third quickest, ahead of Fernando Alonso and Sebastian Vettel.
As ever there were problems with traffic (lots of it) and grip (lack of it) and while there were plenty of spins nobody ended up in the barriers.
This weekend, for the first time this year, we have the supersofts on duty, though it is unlikely we are going to see them just yet.
There is a single DRS zone, with the detection point located 80m after Turn 16 and the activation point located 18m after Turn 19.
The conundrum facing the teams is that while there could be rain on Sunday it is almost certain - according to the weathermen - to be hot and dry tomorrow. There remains a forty percent chance of further rain over the next ninety minutes.
The lights go green but there is no rush to get to work.
Five minutes later an engine fires up and shortly after Bottas heads down the pitlane on a set of inters. Having tip-toed his way around the famous track the Finn heads back to his garage.
Asked about the conditions, the Finn replies that it's "very slippery".
Thirty minutes into the session Bottas remains the only driver to have made an appearance. However, the good news is that a dry line is beginning to emerge.
With 51:05 remaining, Sutil heads down the pitlane, watched carefully by his twenty-one rivals. He is subsequently joined by Kvyat.
While Sutil returns to the pits Kvyat stays out to post a 1:44.982. Elsewhere, Vergne and Alonso leave the pits.
Vergne goes quickest with a 42.484 only to be demoted when his Russian teammate strops the clock at 38.935. Raikkonen and the McLaren duo get to work.
As Alonso goes third (39.613) the Red Bull duo head down the pitlane. It is still quite wet so nobody will be wanting to take any unnecessary risks.
As Kvyat gets it all wrong at Ste Devote Alonso has a moment at Casino and teammate Raikkonen who slows on the pit straight with some sort of technical issue. Alonso, who had just gone quickest (36.038) dives into the pits.
A 35.896 sees Vettel take the top spot as we ride on-board with Magnussen. As the Dane goes quickest (35.805) we appear to be getting close to the time when the drivers can switch to dry tyres.
Button momentarily goes quickest only to be demoted by Vettel (33.780), while in the Ferrari garage Raikkonen is out of his car and loosening his overalls. It doesn't look good for the Iceman.
Replay shows Ricciardo clouting a front-left wheelman as he enters his pit, the price one often pays in the ludicrously tight confines of the Monaco pitlane.