The combination of a sodden track and the limited number of wet and intermediate tyres permitted by the regulations meant it was only when the rain eased off in the second half of the session that drivers began work in earnest.
There was then a further delay when Bruno Senna aquaplaned into the barriers on the way out of the Becketts complex. The heavily-damaged Williams caused a 10-minute red flag period. Senna stepped out unhurt.
Sauber's Kamui Kobayashi was the initial pacesetter, as the Japanese driver showed the same flair that he had in the morning. But his 1m56.474s was then pipped by a 1m56.345s from McLaren driver Hamilton.
That was how the lead order stayed, with Michael Schumacher and Nico Rosberg moving into third and fourth for Mercedes, and Sergio Perez putting the second Sauber fifth. The Mexican subsequently had a big spin coming out of Woodcote.
Although times were relatively meaningless in the conditions, Heikki Kovalainen's seventh place to Caterham was certainly noteworthy. The Finn was yet another man to go off the road, although his incident was limited to a messy trip through a big puddle in the grass.