The final two Friday practice sessions were dominated by persistent rain and grey skies over Interlagos, with the forecast just as gloomy for the remainder of the weekend.
Remarkably, there has yet to be a wet race this season, yet that is on the cards for when the chequered flag falls on the campaign, much to Hamilton's dismay.
Normally a master of the wet conditions, Hamilton has struggled this season in his Mercedes, as evidenced twice during practice.
Hamilton suffered one minor off-track excursion in FP1 before a spin through 360 degrees when the conditions were at their worst in FP2, with the 28-year-old controlling it before rejoining the circuit.
Although Hamilton ultimately finished second quickest overall based on the FP1 times to team-mate Nico Rosberg, he fears the worst this weekend should the forecast prove correct.
"Looking back on my career, in the rain was when I could really make the difference, but in this car there is no hope for me," Hamilton said.
"I don't know what's going on. I'm just really, really struggling with the throttle mapping and all these kinds of things.
"Clearly, the car is quick enough because of what Nico was able to do so I really need to work hard, but I'm just struggling to keep it on the track.
"I'd really prefer a dry weekend, but that's out of our hands."
Rosberg finished top of the timesheet at the end of both sessions, and in contrast to Hamilton would be happy with a wet race.
"In general it looked like good pace, so for me it can stay wet this weekend," Rosberg said.
"I don't know if pole in the wet is possible, it's too early to say, but I've a good shot at being right at the front in qualifying."
At this stage it would appear rain is the only factor that could scupper Sebastian Vettel's bid to equal a further two records on Sunday.
Vettel can match the 60-year-old mark of nine consecutive victories set by Alberto Ascari, along with Michael Schumacher's 2004 haul of 13 wins in one season.
Come rain or shine Vettel usually excels, but there is no guarantee of what might happen around him, adding an unknown element into the mix and the need to be focused.
"We knew it would be wet and might be tricky, but it was good to get a bit of a baseline in these conditions," Vettel said.
"Now we need to be sharp for the next two days and make the right calls."