A polar air mass is bringing sub-zero temperatures and the risk of snow to Brazil's Centro-Sul region on Thursday, June 25, 2026 [1].

This weather event is significant because it affects a vast area including the South, Southeast, and parts of the Central-West, potentially impacting agriculture and infrastructure through severe frost [2].

The cold wave is driven by a polar front moving southward across the country [3]. Meteorologists said the peak of this cold spell occurs on Wednesday and Thursday, with the latter seeing intensified conditions [1]. In the Southern states, temperatures are expected to drop below 0 °C [1].

Local authorities in Parana have issued alerts for strong frosts [2]. These conditions create a high probability of frost in the South and Southeast, with a specific possibility of snow appearing in the Southernmost states [2, 3].

The movement of the polar air mass has created a widespread cooling effect across the Centro-Sul region [3]. This atmospheric shift brings not only the drop in temperature, but also the potential for precipitation in the form of snow or freezing rain in high-altitude areas [2].

Residents are advised to prepare for the extreme cold as the front continues its progression [1]. The intersection of the polar air mass and local moisture levels increases the likelihood of record-breaking cold in certain jurisdictions [2].

“Temperatures are expected to drop below 0 °C”

The arrival of a polar air mass in June aligns with the Southern Hemisphere's winter, but the risk of sub-zero temperatures and snow in the Centro-Sul region indicates a severe weather event. Such conditions can lead to significant crop loss due to frost, particularly in the agricultural hubs of Parana and the wider South, while placing stress on energy grids as heating demand spikes.