“Vegetables, being extremely sensitive, may have suffered losses of over 90% in some areas…”
Amanda Balbino is a meteorologist at Ampere Consultoria, with a bachelor’s degree in Atmospheric Sciences from the Federal University of Itajubá.
Amanda Balbino, Ampere Consultoria
Between late June and early July, two cold fronts severely impacted the Center-South region of Brazil, causing significant damage to various crops. The third cold front of the year occurred from June 23rd to 25th and was marked by sub-zero temperatures in several regions, even including snowfall in cities in the State of Santa Catarina. In addition, the fourth cold wave, at the turn of June to July, caused temperatures to drop even further: in some regions in the State of Santa Catarina, thermometers reached low temperatures of around -10°C, reinforcing the extreme cold scenario at the beginning of this winter.
The series of cold waves that hit Brazil was caused by the passage of cold fronts that advanced from the south toward the rest of the country, bringing polar air and causing temperatures to drop. An important factor behind this intense shift in the second half of June was the Antarctic Oscillation (AAO), the main mode of climate variability in the Southern Hemisphere, with a direct influence on weather patterns in South America. During this period, the AAO reflected a weakening of winds around Antarctica, facilitating the incursion of polar air into mid-latitudes and tropical regions, as if the “doors were open” for the cold. This then favored the arrival of more intense cold air masses in Brazil.
In recent weeks, these polar air masses have created ideal conditions for frost formation in many agricultural regions. Normally, clear skies in the early morning, without clouds that would act as a kind of “blanket,” allow for greater heat loss from the surface, intensifying nighttime cooling. These factors further increased the drop in temperatures, favoring the formation of frost in several regions. When the temperature drops below 2°C and the winds remain calm, cold air tends to concentrate near the ground, creating an environment conducive to frost formation. Under these conditions, the risk of damage to plants increases significantly, especially for more sensitive crops or those still in the early stages of development.
Impacts on crops
The cold wave from June 23 to 25 strongly affected the State of Paraná, with significant impacts on corn, wheat, vegetable, and pasture crops. Estimates from the Technical and Economic Department (DTE) of the Paraná State Agricultural Federation (FAEP) indicate losses of around 30% in corn production and 20% to 25% in wheat production. Vegetables, being extremely sensitive, may have suffered losses of over 90% in some areas.
The coffee-producing regions in the South of Minas Gerais and Alta Mogiana also felt the effects of the frost. Although the current season (2025) is already well advanced, the cold weather has raised concerns about the 2026 season. This is because frost can damage branches and compromise the productive potential of the next cycle. In addition to reducing yields, intense cold can affect the quality of the coffee beans, which directly impacts market prices.
Furthermore, in recent weeks, frosts have hit sugarcane crops in States such as Mato Grosso do Sul, Minas Gerais, São Paulo, and Paraná. With temperatures close to or below 0°C, many sugarcane fields showed burnt leaves, cracks in the stalks, and death of the apical buds, damage that reduces agricultural performance and requires immediate technical action to contain the losses.
In the south of the country, frosts burned the younger leaves of tobacco plantations, leaving them darkened and brittle. This can compromise both the appearance and quality of the final product.
Cotton, whose 2024/25 harvest is currently underway, faces delays due to unseasonal rains combined with low temperatures. Rainfall in important producing areas, such as Mato Grosso and Mato Grosso do Sul, makes it difficult for machines to enter the fields and jeopardizes the quality of the lint. Harvesting in wet weather also increases marketing standards, causing even more concern for industry players.
What to expect going forward?
Winter is still underway, and the possibility of new cold spells cannot be ruled out. Although July is marked by a dry spell and rising temperatures across the country, forecasts suggest that rains will return between the end of the month and continue into August in the southern region. Therefore, it is essential that farmers stay informed and follow weather reports closely. After all, constant monitoring of the climate enables the adoption of management strategies, which are fundamental to mitigating risks and protecting what is in the field.
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