Brazil officially entered the winter season on Sunday, May 21, 2026 [1], as a polar air mass brought the year's lowest temperatures.
This sudden drop in temperature is significant because it coincides with the winter solstice, the shortest day of the year [2]. The extreme weather is being driven by a strong polar air mass intensified by the El Niño phenomenon [1, 5].
The cold front affected multiple regions, including São Paulo, Paraná, Santa Catarina, and Minas Gerais. In the capital of São Paulo, the temperature did not exceed 18 °C [3]. The state's Civil Defense said this marked the coldest day of the year for the city [3].
Further south, the impact was more severe. Santa Catarina faced forecasts of temperatures as low as -4 °C [4], potentially marking the coldest recording in the country for the year. In Paraná, however, the coldest day of 2026 had already occurred earlier this month on May 10 [4].
"A nova onda de frio chega antes da mudança de estação, trazendo temperaturas mais baixas," the O Estado de S. Paulo editorial team said [1].
The polar air mass also reached Minas Gerais, marking the first significant polar event of the year for the region [5]. Officials said minimum temperatures in Belo Horizonte were expected to drop between eight and nine °C [5].
"O solstício de inverno acontece neste domingo, marcando o dia mais curto do ano," MSN Entertainment staff said [2].
“Brazil officially entered the winter season on Sunday, May 21, 2026”
The alignment of the winter solstice with a strong polar air mass, further amplified by El Niño, suggests a more volatile start to the 2026 winter season than usual. The regional variation in 'coldest day' dates indicates that while some states experienced early peaks in May, the broader national trend is shifting toward extreme lows as the season officially begins.
