A new polar air mass is expected to lower temperatures across the Central-South region of Brazil starting Sunday, May 17, 2026 [1].
This shift in weather patterns follows a brief period of warming, signaling a return to colder conditions that could impact agriculture and daily routines across several states. The arrival of the cold front brings a combination of low temperatures and increased cloud cover.
According to a report from Canal Rural, cold fronts and excessive cloudiness are expected to prolong the low temperatures beginning Sunday [1]. The weather system is characterized by a persistent chill that will settle over the region, altering the typical patterns for the second half of the month.
This cooling trend follows a recent fluctuation in the regional climate. An editorial from ND Mais said that despite a rise in temperatures that began on Wednesday, May 13, 2026 [2], new instability is bringing rain and a drop in thermometers in the coming days [2].
The transition from the mid-month warmth to a polar influence creates a volatile weather window. The current forecast indicates that the Central-South region will remain the primary area affected by this mass of polar air, leading to a sustained period of cold weather and overcast skies.
Meteorologists said that the interaction between the polar air and existing atmospheric instability often results in precipitation. This combination of rain and falling temperatures typically accelerates the cooling process across the Brazilian highlands and southern plains.
“Frentes frias e excesso de nebulosidade devem prolongar temperaturas baixas a partir de domingo”
The arrival of a polar air mass in mid-May indicates a strong seasonal transition for the Central-South region of Brazil. Because this cold front follows a brief warming period, the sudden temperature drop and accompanying rainfall can create challenging conditions for local crop management and public health, as the region adjusts to persistent low temperatures.
