Jenson Button was the quickest man in a highly inconclusive second practice session on the streets of Monaco this afternoon as rain arrived to disrupt proceedings for much of the session. The Briton lapped in a time of 1m15.746s before the rain arrived less than 20 minutes into the 90, meaning no more running on slick tyres.

The sky remained somewhat bright around Monaco for the duration of the session, but lingering cloud directly above the track produced intermittent rain that kept the surface wet enough for intermediate tyres. Other than a few drivers venturing into the various run-off areas around the track, there were no incidents of note, and all stayed clear of the notorious barriers.

When the track was dry early on, Button's time was almost four tenths quicker than the rest of the field, with Lotus's Romain Grosjean again finishing in second place, this time on a 1m16.138s, half a second quicker than his morning practice time. He was followed by Ferrari's Felipe Massa (1m16.602s) and Fernando Alonso (1m16.661s), while Williams' Pastor Maldonado again finished fifth (1m16.820s).

Today's rain coupled with tomorrow's day off mean teams will effectively be starting from scratch when they take to the track again on Saturday morning. Engineers now have an extra day in which to analyse the data gathered during the two sessions, but with rain again forecast for Saturday and Sunday the unpredictability is sure to continue.