A strong polar air mass is expected to bring the first cold wave of winter to Brazil's Centro-Sul region beginning this weekend [1].
This weather event is significant because it marks the official onset of winter's temperature drops for the South, Southeast, and the state of São Paulo. The arrival of an intense polar air mass moving southward is the primary driver behind the expected temperature decline [1, 3].
Forecasters expect the cold wave to begin during the weekend of June 18–19, 2026 [1]. This shift follows a period of fluctuating weather patterns across the country's central and southern territories. The movement of the cold front is expected to impact several states, bringing a sharp contrast to previous temperatures [1, 2].
Reports on the timing of cold weather in the region have varied throughout the season. Some earlier data indicated cold conditions began on Tuesday, May 12, 2026 [4], while other reports noted a cold front entered Brazil on Friday, June 8, 2026 [2]. However, the current forecast identifies this upcoming weekend as the start of the primary winter wave [1].
In São Paulo, the impact of these temperature shifts is closely monitored. Previous projections suggested that low temperatures in the city would remain until Tuesday, June 13, 2026 [5]. The current polar air mass is expected to reinforce these cooling trends as it pushes further into the interior of the Centro-Sul region [1, 3].
Residents in the affected areas are advised to prepare for a significant drop in temperature as the air mass settles over the region. The interaction between the polar front and local geography often leads to prolonged cold spells in the southern highlands [1].
“A strong polar air mass is expected to bring the first cold wave of winter to Brazil's Centro-Sul region.”
The arrival of the first major cold wave of 2026 signals the transition into the winter season for Brazil's southern regions. While sporadic cold fronts occurred in May and early June, the current polar air mass represents a more sustained climatic shift. This can lead to increased energy demand for heating and may impact agricultural cycles in the Centro-Sul region.
