Autumn 2024: When Will Cold Weather Arrive in Brazil?

Santa Catarina officially entered autumn on Friday, March 20th, but unseasonably warm temperatures are persisting across the state, defying typical seasonal transitions. While the calendar marks the shift from summer, forecasts from the National Institute of Meteorology (Inmet) and Climatempo indicate a delayed arrival of significant cold weather for Brazil as a whole.

The autumn season, extending until June 21st, is currently predicted to be characterized by above-average temperatures, with the lingering warmth expected to dominate the initial weeks. Alongside the heat, increased rainfall is anticipated in certain regions.

The first substantial cold front of the autumn season is now projected to reach the country in the second half of April, according to Climatempo. This front is expected to bring cooler temperatures to southern Brazil, as well as parts of the Southeast and Midwest regions. However, more intense cold is not expected until the latter half of May, with the highest probability of significant temperature drops occurring at the end of the month or in early June.

Specific temperature forecasts suggest São Paulo could experience temperatures between 12°C and 14°C during the final week of April, potentially dropping to around 10°C by late May or June. Further south, Curitiba and Porto Alegre may see temperatures fall below 10°C as early as mid-April. Florianópolis is expected to see temperatures near 10°C in early June.

Increased rainfall is expected in the South region due to a coastal El Niño phenomenon, characterized by warming waters off the coasts of Peru and Ecuador. The area between Rio Grande do Sul and Paraná is predicted to be most affected, while the Southeast and Midwest are expected to receive rainfall volumes within the normal range. The Northeast region is as well forecast to experience above-average rainfall, particularly in cities between Salvador and Natal.

Conversely, the North region is expected to receive less rainfall than usual during the autumn season, with the exception of Amapá. The most intense cold is anticipated between May and June, with a potential for frost in southern Brazil, southern Mato Grosso do Sul and parts of São Paulo.