Fernando Alonso edged Lewis Hamilton in final practice at the Hockenheim before the rain came down, bringing an end to the session.
In an attempt to make up for time lost in the wet on Friday, the drivers were quickly down to business with Jean-Eric Vergne posting the first time of the morning, a 1:24.191.
Kimi Raikkonen was the next to lead the way with a 1:20.927 before he was overhauled by Nico Rosberg, who took 2.2s off the Lotus driver's best. The Mercedes driver continued lapping, shaving tenths off his time. The German definitely had an advantage in the opening stint, lowering the benchmark down to a 1:17.491.
Felipe Massa took the fight to Rosberg, the first driver to get within two seconds off the Merc. In fact, he was just 0.144s adrift as the duo appeared to be the only big-name drivers running light fuel loads. Bruno Senna joined the tussle at the front, taking third and then first with a 1:17.391.
Mark Webber was the next to lead the way before losing out to Friday's pace-setter Pastor Maldonado and then Sebastian Vettel, who is chasing his first-ever German Grand Prix victory.
With the drivers determined to get in as much running before the forecast rain arrived, Maldonado again hit the front and then Vettel as the duo traded fastest laps. Webber was third.
Fernando Alonso, who was a late starter as his Ferrari mechanics worked on his brakes, headed out on the softer option tyres and went quickest with a 1:16.124. His time, though, was bettered by Lewis Hamilton despite the McLaren driver being on what should be the slower medium compound tyres.
Alonso returned to the front, 0.077s up on Hamilton as the track temperature heated up to 28'C despite the gathering clouds. With five minutes left in the session the expected rain began to fall, prompting the field to head back into the pits as the minutes counted down and the chequered flag waved.
1 Fernando Alonso Ferrari 1:16.014 14 laps
2 Lewis Hamilton McLaren 1:16.091 0.077 21 laps
3 Sergio Perez Sauber 1:16.202 0.188 21 laps
4 Kimi Raikkonen Lotus 1:16.238 0.224 27 laps
5 Mark Webber Red Bull 1:16.447 0.433 19 laps
6 Sebastian Vettel Red Bull 1:16.475 0.461 18 laps
7 Pastor Maldonado Williams 1:16.664 0.650 18 laps
8 Felipe Massa Ferrari 1:16.771 0.757 15 laps
9 Kamui Kobayashi Sauber 1:16.807 0.793 25 laps
10 Bruno Senna Williams 1:16.930 0.916 23 laps
11 Romain Grosjean Lotus 1:16.962 0.948 26 laps
12 Nico Hulkenberg Force India 1:17.033 1.019 26 laps
13 Paul di Resta Force India 1:17.148 1.134 24 laps
14 Daniel Ricciardo Toro Rosso 1:17.238 1.224 25 laps
15 Michael Schumacher Mercedes 1:17.266 1.252 22 laps
16 Jean-Eric Vergne Toro Rosso 1:17.419 1.405 23 laps
17 Nico Rosberg Mercedes 1:17.491 1.477 26 laps
18 Heikki Kovalainen Caterham 1:18.366 2.352 21 laps
19 Vitaly Petrov Caterham 1:18.818 2.804 23 laps
20 Pedro de la Rosa HRT 1:19.778 3.764 22 laps
21 Timo Glock Marussia 1:20.235 4.221 22 laps
22 Charles Pic Marussia 1:20.318 4.304 9 laps
23 Narain Karthikeyan HRT 1:20.741 4.727 22 laps
24 Jenson Button McLaren 1:20.914 4.900 25 laps