Temperatures are expected to drop below 10°C across the South-Central region of Brazil this Thursday, June 18, 2026 [1].
The sudden cold snap signals the arrival of a polar air mass, creating risks for frost and impacting millions of residents across several states. This weather pattern marks a sharp transition into the winter season for the region.
According to meteorology institutes, including Climatempo, the cold front will affect the states of São Paulo, Minas Gerais, Rio de Janeiro, Espírito Santo, Paraná, Santa Catarina, and Rio Grande do Sul [2, 3]. In the city of São Paulo, the minimum temperature could reach 8°C on Thursday [4].
"Temperatures below 10°C are expected in several cities of the South-Central region, with a risk of frost," Climatempo said [1].
The current dip in temperature is viewed as a precursor to a more sustained cold period. Redação G1 said the first official cold wave of the winter is expected to begin this weekend, which will further drive down temperatures across the South-Central region [5].
The movement of polar air often brings a sequence of negative temperatures in higher altitudes and inland areas [6]. This shift typically disrupts agricultural cycles and increases the demand for heating and energy in urban centers. Local authorities generally advise residents to prepare for the sudden shift in climate to avoid health complications associated with the cold.
“Temperatures below 10°C are expected in several cities of the South-Central region, with a risk of frost.”
The arrival of a polar air mass in June indicates the start of the southern hemisphere's winter cycle. When temperatures drop below 10°C in regions like São Paulo and Minas Gerais, it often leads to agricultural frost that can damage sensitive crops. The transition from a sudden dip to a full cold wave over the weekend suggests a stable high-pressure system is moving in, which may keep temperatures low for several days.
