A powerful polar air mass is set to enter Brazil this week, bringing freezing temperatures across multiple states and record-breaking cold to the South, according to projections from MetSul Meteorologia. Driven by an intense extratropical cyclone moving into the South Atlantic, this system represents the strongest cold front of the year, with thermal levels at 1500 meters of altitude not previously observed in the southern region during 2024.
Did You Know? Unlike maritime-trajectory cold fronts that typically affect coastal areas like Bahia and Rio de Janeiro, this week’s event follows a continental path through the interior of South America, which allows the freezing air to penetrate deep into the Center-West and even parts of the Amazon region.
How the cold will impact different regions
The most severe temperatures are expected to concentrate in the three southern states—Rio Grande do Sul, Santa Catarina, and Paraná—from Tuesday, July 23, through Wednesday, July 24. While the South will face the brunt of the freeze, the cold will also cause noticeable temperature drops in Mato Grosso do Sul and São Paulo. Less significant cooling is anticipated for the North, though a brief drop in temperature is expected in parts of Minas Gerais, southern Goiás, Rondônia, and Acre.
What to expect in the coming days
Following the initial surge of cold, a high-pressure center of 1030 hPa will settle over southern Brazil during the second half of the week. This will result in clear skies, dry air, and calm winds—conditions that promote rapid nocturnal cooling. Between Tuesday (23) and Saturday (27), hundreds of cities across the South are projected to see minimum temperatures near or below 0ºC. In high-altitude areas such as the Campos de Cima da Serra and the Planalto Sul, meteorologists anticipate lows between -5ºC and -7ºC, with some valleys potentially dropping to -8ºC or lower.
Expert Insight: The combination of a strong polar air mass and a subsequent high-pressure system creates a “perfect” scenario for frost. As an editor, I’ve seen these setups before; the danger isn’t just the overnight low, but the lingering impact of ice on infrastructure. Residents in high-altitude zones should prepare for potential travel hazards as road surfaces may freeze, making transit risky even in areas where such conditions are historically rare.
Frequently Asked Questions
Which areas are expected to face the most extreme cold?
The most intense cold is expected in the Campos de Cima da Serra in Rio Grande do Sul, the Planalto Sul of Santa Catarina, and the Planalto de Palmas in Paraná.
When will Porto Alegre experience the coldest temperatures?
The coldest mornings in Porto Alegre are expected between Tuesday, July 23, and Saturday, July 26, with some metropolitan areas potentially reaching 0ºC to 2ºC.
Will this cold front cause frost?
Yes, a high number of cities in the South and the Center-South of Mato Grosso do Sul are expected to experience frost, with risks of ice on roads and streets in higher-altitude locations.
How are you preparing for the extreme temperatures forecasted for your region this week?
