For close to two weeks, political parties have campaigned rain or shine, increasingly the former as the northeast monsoon brings the heavy rain and flash floods associated with the end of the year.
Voters and supporters, for their part, have rallied, gathering for political talks and campaign events even if it means sitting in the dark with rain pouring down overhead.
But while the rain has meant nothing more than showers and wet crowds in some areas, it has meant storms and flash floods in others such as Putrajaya, Shah Alam and Klang.
There, residents are still fearful of a repeat of the large-scale floods which swept across several states last year.
A number have said that they might not go out to vote if it floods again this year.
Malaysian Meteorological Department (MetMalaysia) deputy director-general (operations) Lim Ze Hui said several states are expected to experience heavy rain in the morning on voting day.
However, he said there is no cause for concern as the rain is not likely to continue past noon.
The states in question are Kelantan, Terengganu, Selangor, Negeri Sembilan, Melaka, Johor as well as the west part of Sarawak and the north of Sabah.
In the evening, meanwhile, thunderstorms are expected in the interior of the peninsula and in Sabah and Sarawak.
"In general, we do not expect heavy continuous rain on polling day," Lim said in an exclusive interview with MalaysiaNow.
When asked about the possibility of floods similar to those that occurred last December, Lim said it was difficult to predict the intensity of rainfall.
"We can predict rain and thunderstorms, but how heavy the rain will be during that time is hard to tell," he said.
In the event of a worrisome weather forecast, he said, MetMalaysia would issue a public warning.
"The relevant agencies will take this data before deciding on further action," he said, adding that MetMalaysia is part of the National Disaster Management Agency or Nadma.
Meanwhile, Hisommudin Bakar, the executive director of electoral think tank Ilham Centre, said surveys showed that 80% of voters intended to cast their ballots despite forecasts of floods in their areas.
"In general, they will turn out to vote," he said. "Among the youth, 90% want to vote because they are excited about casting their ballots for the first time.
"But this will be put to the test if floods do occur in their areas."
Political observer Azizi Safar said voters of all stripes would be affected if it floods.
"If it floods on polling day, this could trigger the anger of voters in general," he said.
"The party that called for the election to be held this year despite the threat of floods will bear the brunt of that anger."
Nevertheless, he said the voter turnout would be lower in areas that experience bad weather on polling day.
"If it floods to the point that the voting process is affected, the Election Commission might take the necessary measures to address the situation," he said.
"In this case, it's possible that the polling date will be changed or postponed."