A polar air mass moving southward across Brazil triggered a severe cold wave and frost across the South, Southeast, and Central-West regions [1, 5].
This weather event disrupted typical seasonal patterns, bringing record-low temperatures to urban centers and agricultural zones. The intensity of the cold front created risks for public health and crop stability in several states.
The Instituto Nacional de Meteorologia (Inmet) and weather teams said that the cold front brought significant temperature drops [1]. In São Paulo, the minimum temperature reached 2°C [2], while Mato Grosso do Sul recorded a minimum of 5°C [2]. These conditions led to the occurrence of geadas, or frosts, in the affected regions [2, 3].
According to reports, the most intense period of the cold wave occurred on May 12, 2026 [3]. The polar air mass created a strong cold front that pushed deep into the interior of the country [5].
Weather officials said that the cold air began to lose intensity between May 13 and May 14, 2026 [4]. Following this peak, temperatures were expected to rise again in the Southeast and Central-West regions [4].
While some earlier reports in April suggested heat would predominate in these areas, the subsequent polar surge shifted the climate rapidly toward extreme cold [6]. The movement of the air mass ensured that the South, Southeast, and Central-West states experienced the most severe impact of the system [2, 3].
“The minimum temperature reached 2°C in São Paulo.”
The rapid transition from predicted warmth to record-breaking cold underscores the volatility of polar air mass movements in South America. When temperatures drop to 2°C in regions like São Paulo, it can lead to significant agricultural losses due to frost and put pressure on energy grids as heating demand spikes in areas not fully equipped for extreme cold.
