Rescuers continued to search for victims on the third day since the catastrophe began late Monday, causing floods, landslides, collapsed houses and shuttered schools.
Minas Gerais's fire department said 15 people are still missing and more than 230 have been rescued.
Brazil's meteorology institute, Inmet, said on Thursday morning that more rain with strong winds was forecast, and pointed to a risk of power outages, falling tree branches, flooding and lightning strikes.
"This morning, all the shops in the city centre are being cleaned again. The storm on Monday already caused damage, and early this morning there was even more damage," said Rev. Ananias Simões, a pastor at a church in Juiz de Fora, the hardest-hit city.
All the victims have been found in Juiz de Fora and Uba, about 310 km north of Rio de Janeiro.
Simões, whose church is providing shelter and supplies for victims, said that many roads were closed due to the expectation of more heavy rain. Despite logistical difficulties, he planned on going to the city's heavily affected northern zone to deliver food and water.
"The situation is very chaotic," he said. "Everyone is doing their utmost to make sure everyone stays safe."
The fire department has advised residents to look for signs that their properties may have been damaged or are at risk of collapse, such as cracks in bulging walls, fissures and stuck doors and windows. Outside, muddy water flowing down hillsides, leaning trees and utility poles and cracking sounds coming from the ground all signal imminent danger, it said.
President Luiz Inácio Lula da Silva said on his social media channels on Tuesday that security forces have been deployed on rescue missions and are providing immediate assistance to the population affected by the rain.
Scientists say extreme weather is happening more frequently due to human-caused climate change.
Massive flooding in Brazil's southern Rio Grande do Sul state in May 2024 led to the deaths of at least 185 people and ravaged nearly everything needed for economic activity, from shops to factories, farms and ranches. Financial losses were above 10 billion reais ($A2.7 billion)).
