A polar air mass is moving through Southern Brazil, bringing temperatures to or below 0°C in parts of the region [1, 2].
This cold front represents a significant shift in weather patterns for the states of Rio Grande do Sul and Santa Catarina. The sudden drop in temperature during the autumn season creates immediate challenges for agriculture, and public health in the Southern highlands.
The most intense cold is expected during the weekend of May 5-6 [2]. In Santa Catarina, forecasts indicate a minimum temperature of -4°C [2]. This dip could mark the coldest day of the year for the state [2].
Recent readings in São Joaquim, located within the Serra Catarinense region, have already recorded a temperature of -3.33°C [2]. The arrival of the polar air mass follows a period of volatility that began earlier this year, including a cold front that affected the country during the weekend of Feb. 20-21 [3].
While the South faces freezing conditions, other regions of Brazil have experienced different shifts. Earlier reports indicated that Minas Gerais saw temperatures drop up to eight degrees Celsius lower than recent days due to cold front activity [3]. The current weather cycle follows the official start of the 2026 Brazilian autumn, which began on March 20 [4].
Despite the freezing forecasts in the highlands, some reports suggest that extreme lows below -10°C are not predicted for the region. The primary impact remains concentrated in the high-altitude areas of Santa Catarina, and the neighboring state of Rio Grande do Sul [1, 2].
“Forecasts indicate a minimum temperature of -4°C in Santa Catarina.”
The arrival of a polar air mass in May suggests a strong seasonal transition for Southern Brazil. While sub-zero temperatures are not uncommon in the Serra Catarinense, the timing and intensity of this front can disrupt local crop cycles and strain energy grids as demand for heating increases in regions not fully equipped for extreme cold.
