How Is Weather Affecting South American Crops?

After a lack of rain in January and last week’s heatwave brought temperatures as high as 104°F, parts of Brazil and Argentina are expected to receive rain in the coming week, according to David Tolleris, meteorologist and owner of WxRisk. 

The rain is especially welcome in Argentina, ahead of the corn and first-crop soybean harvests. 

“If these rains show up in the next week in Argentina, that’s going to help,” Tolleris said. “But I think the damage has already been done.” 

South American Production Outlook Cuts

The U.S. Department of Agriculture (USDA) reduced its outlook for Argentina’s corn and soybean production in the February World Agricultural Supply and Demand Estimates (WASDE). The projected corn crop was cut by 1 million metric tons (mmt), down to a projected 50 mmt. Soybean estimates were cut by 3 mmt, a decrease to 49 mmt. The corn crop in Brazil was also cut by 1 mmt, reduced to 126 mmt. Its soybean production remained unchanged at 169 mmt. 

Tolleris said that in the past week, Mato Grosso, Brazil’s top soybean-producing state, received about 6 inches of rain. Tolleris said to keep an eye out for the rest of February, and if Brazil gets the expected precipitation. He said some climate models are predicting a drier March in Brazil. 

“If these rains show up in the second half of February for Brazil, that means whatever dryness concerns you have for March are greatly alleviated because it’ll be pretty wet,” Tolleris said. 

Weather Impacts Harvest and Planting Progress

According to a report by agribusiness consultancy AgRural, the 2024–2025 soybean harvest in Brazil is 15% complete, while 20% of the second-crop corn has been planted in the center-south region. This is 18 percentage points behind last year’s second-crop corn, when 38% was planted. The second-crop corn makes up about 75% of the country’s total production. AgRural also said producers in Mato Grosso and Goiás, which make up nearly 50% of Brazil’s corn production, are concerned about hitting the ideal planting window, which ends at the end of February. 

Tolleris said that the Madden Julian Oscillation, an atmospheric weather model, is moving into phases 8 and 1, which typically bring precipitation to South America. However, other forecasting models are showing continued dryness throughout the rest of Brazil for the next two weeks, with “no significant rains” to be accounted for. 

“March becomes even more critical because if you have a dry February and then go into a dry March, then you don’t have any moisture in the ground to work with,” Tolleris said.