Lewis Hamilton set the pace in Thursday's second practice in Monaco, however, there was only 14 minutes of dry running before a crash and the rain.
With dark clouds threatening overhead, the drivers immediately got into the action at the Monte Carlo cirucit on Thursday afternoon.
Within 15 minutes, 19 of the 20 drivers had posted lap times with Lewis Hamilton quickest on a 1:17.192 while Nico Rosberg was 0.740s slower than his team-mate.
Sebastian Vettel was third fastest ahead of Kimi Raikkonen, Daniil Kvyat and Carlos Sainz.
Their running, though, was paused 14 minutes into FP2 when Roberto Merhi brought out the weekend's first red flags.
The Manor rookie got out of shape on the brakes exiting the tunnel and the end result was his car snapped into the barriers, damaging the front.
The crash brought out the red flags, which were waved for six minutes before FP2 resumed. However when it did, the rain was falling.
Pastor Maldonado made a brief – and questionable – run using the soft tyres and, after almost putting his E23 into the barrier, crawled back to the pits declaring that it is "raining too much."
The rain let up with 30 minutes remaining but by then the circuit was thoroughly soaked. Some of the drivers did opt to venture out in the final 10 minutes using the intermediate Pirelli tyres, although Rosberg and Sergio Perez bucked the trend using the full wets. Hamilton made the swap for the final two minutes.
Some 20 seconds down on their dry times, Jenson Button complained about "very low grip" while Kvyat used the escape road at Ste Devote. Those who did opt to put in a few laps in the wet all managed to keep the cars off the barriers.
1 Lewis Hamilton Mercedes 1:17.192 13 laps
2 Nico Rosberg Mercedes 1:17.932 0.740 16 laps
3 Sebastian Vettel Ferrari 1:18.295 1.103 15 laps
4 Kimi Raikkonen Ferrari 1:18.543 1.351 16 laps
5 Daniil Kvyat Red Bull 1:18.548 1.356 17 laps
6 Carlos Sainz Toro Rosso 1:18.659 1.467 15 laps
7 Max Verstappen Toro Rosso 1:18.782 1.590 13 laps
8 Fernando Alonso McLaren 1:18.906 1.714 19 laps
9 Nico Hulkenberg Force India 1:19.151 1.959 13 laps
10 Romain Grosjean Lotus 1:19.266 2.074 13 laps
11 Sergio Perez Force India 1:19.300 2.108 14 laps
12 Felipe Massa Williams 1:19.560 2.368 16 laps
13 Valtteri Bottas Williams 1:19.566 2.374 15 laps
14 Pastor Maldonado Lotus 1:19.577 2.385 13 laps
15 Jenson Button McLaren 1:19.606 2.414 15 laps
16 Daniel Ricciardo Red Bull 1:19.639 2.447 14 laps
17 Felipe Nasr Sauber 1:20.263 3.071 11 laps
18 Roberto Merhi Manor 1:22.017 4.825 10 laps
19 Will Stevens Manor 1:22.943 5.751 14 laps
20 Marcus Ericsson Sauber No time 0 laps