The 2008 world champion, who led much of the race, pitted six times, including a drive-through penalty."I was struggling a lot with the graining on my left front tyres," said Hamilton. "I don't know whether that was my fault, pushing too much.
"We would have liked a one-two. I let the team down a little bit but we will be back."
Red Bull's Sebastian Vettel made a clean getaway from pole to stay ahead of Hamilton, however, the McLaren driver was clearly the faster of the two in changeable conditions.
Hamilton passed Vettel on lap five after the German ran wide at Turn Two and began to build a lead at the front.
But his decision to pit for more option tyres on lap 41, when his rivals - including team-mate and eventual race winner Jenson Button - chose the primes, proved to be the wrong one as he would have to stop again.
When the rain came, Hamilton decided to switch to intermediates, but the wet weather didn't last and he was forced to make a fifth stop for the primes.
"We were having radio issues," added Hamilton. "I could hear my engineers but they couldn't hear me.
"I heard them say it was going to rain and it was already spitting so we opted to go for the wet tyres. It wasn't necessarily the best call, but that's motor racing."
A drive-through penalty, for forcing Paul di Resta's Force India off track after a spin, dropped him further back, but his fresher tyres helped him to pass Red Bull's Mark Webber for fourth.
"My left front tyre was pretty worn so I went a bit wide, came out of the chicane and spun which is very, very rare for me. I think it's one of the first times I've spun," said Hamilton.
Reflecting on the Button's win, Hamilton added: "Jenson was pushing me hard the whole race and the better man won today.
"For us to have been the most competitive cars this weekend means we go into the break in good spirits."
Source: BBC Sport
