A polar air mass brought intense cold and frost to southern and southeastern Brazil during the week of May 12, 2026 [4].
This weather event represents a significant temperature drop for the region, impacting agriculture and public health through early-morning freezes and record-breaking lows.
The cold front moved across the country starting Monday, May 12, 2026 [4]. It brought a sharp drop in temperatures due to the arrival of a new polar air mass [5]. The system affected the southern states of Rio Grande do Sul and Santa Catarina, as well as southeastern states including São Paulo, Minas Gerais, and Espírito Santo [1].
In the southeast, São Paulo recorded a minimum temperature of two °C [2]. Meanwhile, Mato Grosso do Sul saw temperatures drop to five °C [1]. In the southernmost regions, the cold was even more severe, with forecasts indicating temperatures would fall below zero °C in Santa Catarina and Rio Grande do Sul [3].
Weather reports from the period showed varying levels of intensity across the regions. On May 13, 2026, the G1 editorial team said, "Frio segue intenso no Sul e dá uma trégua em parte do Sudeste" [1]. However, other reports indicated the front continued to bring instability. An R7 weather correspondent said, "A chuva vai atingir Minas Gerais e Espírito Santo, enquanto o frio ganha força em parte do país" [3].
The system caused widespread frost in the early mornings of the week. While some analysts noted a brief relief in parts of the southeast, others reported that the region continued to experience record-breaking cold [1, 2]. A Climatempo analyst said, "Enquanto o tempo firme permanece em grande parte do Sul, áreas do Sudeste seguem sob influência de uma ..." [6].
The combination of heavy rain in the southeast and freezing temperatures in the south created a volatile weather pattern across the center-south of Brazil. This polar surge reinforced the cold wave that had already begun to settle over the southern states [3].
“Minimum temperatures recorded in São Paulo reached two °C.”
The penetration of polar air masses into the southeastern states of Brazil often disrupts local agricultural cycles, particularly for frost-sensitive crops. When temperatures drop to two °C or below in regions like São Paulo, it indicates a strong atmospheric shift that can lead to significant crop loss and increased energy demand for heating in urban centers.
