The summer season of 2024/2025 officially commenced on December 21, bringing with it predictions of diverse weather patterns across Brazil. The Instituto Nacional de Meteorologia (INMET) confirms significant rainfall is expected particularly affecting the Central and Northern regions. This year, the influence of the La Niña phenomenon is anticipated to be weaker, and its effects may taper off quicker than usual. According to forecasts, there is a 60% probability of such conditions prevailing from January to March, decreasing to 40% between February and April 2025.
While the North is expected to witness above-average rainfall, the Northeast is projected to have lesser amounts overall. An expert from INMET notes, "Even with the forecast indicating lesser rainfall overall, the northwest part of the Northeast may experience heavy rains during summer." Precipitation forecasts suggest the South may see average rainfall or below-average amounts, with particularly lower totals expected in Rio Grande do Sul.
The consequences of these weather patterns may extend beyond mere inconvenience. The INMET report highlights potential impacts on economic sectors such as agriculture and hydroelectric energy generation. Therefore, farmers could face difficulties with crop growing conditions, and hydroelectric plants may see reduced efficiency due to inconsistent water levels.
Adding to the seasonal challenges, beachgoers may encounter compromised water quality at various hotspots. Recent assessments reveal worrying trends at some of the most frequented beaches, including Tambaú and Bessa 1, classified as having significantly poor water quality. The Tambaú beach, once rated good, has slipped to regular, and Bessa 1 is now deemed poor. The situation poses health risks for bathers, especially as the hot season attracts more visitors to coastal areas. The upcoming summer could see increased warnings for public health hazards as bathing conditions worsen.
Instances from the evaluations performed from previous summers indicate the severity of this issue. Notably, from 2021 to 2024, only Coqueirinho and Jacumã maintained satisfactory water quality. Reports indicate beaches like Baía da Traição and Campina have improved ratings since 2020. Nevertheless, the deteriorated conditions at popular sites have raised alarms among environmental and health officials.
Across other areas, the southern regions of Minas Gerais are bracing for severe thunderstorms early this summer, following rainstorms from the past weeks. Pouso Alegre faced urban flooding and tree falls due to adverse weather just before the summer solstice hit. The INMET has issued warnings for various regions, emphasizing the potential for heavy downpours and even hail, primarily affecting the northeastern and southeastern parts of the state.
While many embrace the warmth and leisure of summer, this year's principal focus remains on the unpredictable nature of the weather. Enhanced moisture transport between the Northern and Central-Western regions is likely to create conditions for the Zona de Convergência do Atlântico Sul (ZCAS), which usually leads to heightened rainfall and storms. Meteorologists predict frequent formation of corridors of moisture flowing through these regions, contributing significantly to summer instability.
On one hand, temperatures are projected to remain near average, with some areas like southern Brazil potentially experiencing localized heat waves. Fábio Luengo of Climatempo explains, "This summer is set to be unlike those of recent years, with insufficient heat wave influences and limited impacts from El Niño and La Niña." This Summer is expected to produce ample rainfall with moderated heat, diverging from the exceedingly hot summers previously experienced across the country. Across regions, forecasts suggest fluctuations from slightly above to slightly below average temperatures.
Different areas will experience varied summer conditions. The South may face sporadic, irregular rainfall, leaving some areas dry, particularly affecting states like Santa Catarina and Paraná. Meanwhile, the Central-West will likely see more rainfall, particularly concerning for agricultural stakeholders aiming for bountiful harvests.
For the Northeast, meteorologists predict erratic rainfall patterns, impacting temperatures earlier this January. Some regions can expect high levels of humidity favoring sporadic rainfall amid otherwise high temperatures. The North, too, is anticipated to endure warmer conditions, characterized by continuing high moisture levels but insufficient rainfall compared to seasonal averages.
Overall, the arrival of the hot summer months brings with it mixed blessings. While the chance for various economic impacts and health risks are prevalent concerns, there remain opportunities for beneficial rain patterns supporting regional agricultural needs. Whether for leisure at the beaches or managing agricultural outputs, Brazilians across the country must brace themselves for the diverse weather challenges and opportunities this summer season will present.