The autumn of 2025 marks a significant climatic transition in Brazil as it begins on March 20, 2025, at 6:01 AM and extends until June 20, 2025, at 11:42 PM.
During this period, the country is expected to experience a range of weather conditions, notably above-average temperatures and below-average rainfall in many regions, further intensified by ongoing climate change effects.
As the Southern Hemisphere moves into autumn, temperatures are anticipated to remain higher than usual due to various climatic factors, including the neutrality of the El Niño and La Niña phenomena, leading to traditionally warmer conditions.
According to the National Institute of Meteorology (Inmet), March 20 marks not only the beginning of autumn but also a significant shift in weather patterns. This year’s autumn avoids the drastic weather extremes seen in 2024, which were largely influenced by a strong El Niño effect that caused catastrophic flooding in parts of Rio Grande do Sul.
Forecasts reveal that autumn will bring mostly clear skies, particularly in the South, Southeast, and Midwest regions of Brazil. Andrea Ramos, a meteorologist, states, “The start of autumn will maintain elements of summer, with higher temperatures throughout April and part of May.”
While the initial phase of autumn will witness persisting warm days, particularly in April, the month of May is expected to be notably warmer than average in the Southeast and Midwest. Temperatures above normal are already forecasted across much of Brazil.
The autumn of 2025 will deviate from previous years in several respects. Meteorologists expect clear skies alongside a mild climate due to the lack of strong climatic events, which typically disrupt traditional weather patterns.
This year, however, the Civil Defense has indicated a general reduction in rainfall over the next months, making dry periods more frequent across various regions of the country. Reports on March 19, 2025, noted the expectation of decreasing rainfall, with dry conditions becoming the norm.
In addition to temperature and rainfall changes, the arrival of autumn will also bring about variations in humidity levels across the nation. The drier air, particularly in the afternoons, has raised health concerns, prompting calls for increased hydration and awareness of respiratory issues, especially for vulnerable groups.
Moreover, due to the expected reduction in humidity, the formation of fog and mist will become more prevalent during the early morning hours, impacting visibility in urban areas and along highways. As the nights become longer, the air will cool down significantly, increasing the likelihood of frost in colder regions.
The weather is anticipated to shift from summer rain patterns to those typical of cold fronts and lower-pressure systems. Autumn 2025 is set to feature occasional extreme weather events such as extratropical cyclones, particularly affecting the southern parts of the country.
The transition from summer to autumn will be gradual, primarily characterized by increased variability in temperature. The last weeks of March and April could still see significant rainfall before it tapers in May, with areas in the North experiencing increased precipitation due to the persistent influence of the Intertropical Convergence Zone (ITCZ).
The final inspection on climatic expectations for South Brazil states that after the warm spell in April, temperatures may become erratic, with some days feeling unusually cool due to cold air masses moving in from the south. Andrea Ramos explains, “The temperatures in late autumn, especially in southern regions, might show sudden drops, leading to frost and potentially snow on the higher grounds.”
As a result, the National Meteorology Institute indicates that, while some regions may notice a spike in warm days, colder nights are anticipated, especially in areas prone to temperature swings.
Severe weather precautions are warranted, especially as the forecast indicates a likelihood of intense cyclonic events. Urban centers, particularly those near the coast, should prepare for increased winds and the possibility of frosty conditions.
The autumn of 2025 is poised to be memorable. It will showcase a captivating climate shift characterized by clear skies, warm temperatures, and the potential for unusual weather occurrences. Residents are encouraged to stay informed about weather updates and prepare accordingly for the upcoming months.
As the weather evolves, citizens should watch closely for how these atypical patterns manifest within their local forecasts; autumn 2025 undoubtedly promises to be a distinctive season marked by its unpredictability.
