Throughout the course of the two 90-minute practice sessions the rain was unrelenting, and for a lengthy period at the start of the afternoon run the drivers took shelter in their garages.
At the top of the timesheet it was Hamilton who led the way in his McLaren, but with times relatively meaningless given the conditions, even for a Friday.
The 27-year-old, who won by 68.5 seconds four years ago for arguably the greatest victory of his Formula 1 career, posted a time of one minute 56.345secs.
Sauber’s Kamui Kobayashi, who completed the most laps early on with 19, also posted an afternoon-high of 16, with his best 0.129secs within Hamilton.
Seven-times champion Michael Schumacher, renowned for his skills in the rain over the years, was exactly two-tenths of a second behind Hamilton, while team-mate Nico Rosberg was 0.222secs off the pace.
Sauber’s Sergio Perez was the best of the rest, but almost a further second down, followed by Jenson Button in his McLaren, the 32-year-old 1.603secs behind his team-mate. The remainder were over two seconds off, led by Heikki Kovalainen in his Caterham and Lotus’ Kimi Raikkonen. As for Fernando Alonso, he was tenth, with Force India’s Paul di Resta 11th.