The weak cold front that passed through the region over the weekend sprinkled a few light, scattered showers in Parana and Minas Gerais, but nothing that interrupted harvesting.
A new cold front is due in the region on Friday but only trace amounts of scattered showers are expected in some of the main coffee producing areas, Somar said.
"The coffee belt can expect mostly clear weather for the next two weeks," Nadja Marinho, meteorologist for Somar, told Reuters.
In its extended forecast, Somar said two other cold fronts were headed for southern Brazil in the first two weeks of September, but only limited rain was expected.
The first one will enter on September 8-9 with little chance of rain, while the second on September 12-13 shows more potential for rain over the coffee belt.
"We're forecasting light showers from the second front, which is not much when you consider that it will be the only rain in the region for about two weeks," Marinho said.
Temperatures will drop with the arrival of the second front but there is no risk of frost.
"The coffee belt is now virtually out of its frost season," she added.
No crop damaging frost has affected Brazilian coffee trees this season.