Inmet forecasts September with above-average heat and regular rainfall

September is expected to see rainfall close to the historical average across much of Brazil, according to a forecast from the National Institute of Meteorology (Inmet) released this Monday (August 25). Temperatures, however, are expected to be higher than expected in several regions, particularly southwestern Pará and the border between Goiás and Minas Gerais, where temperatures could register up to 8°C above normal, ranging from 1,5°C to 27°C.

Rain

In the North Region, rainfall amounts up to 50 mm below the historical average are expected in areas of Roraima, south-central Pará, Acre, Rondônia, and isolated areas of Amazonas. On the other hand, northern Amazonas could see accumulated rainfall exceeding 160 mm, while the extreme northeast of Pará is expected to see rainfall exceeding 100 mm.

In the Northeast, the forecast indicates volumes close to average, except in the coastal strip of northeastern Bahia, which should register a deficit of up to 50 mm.

In the Center-West and Southeast, the trend is for rainfall within normal limits, with exceptions: sectors of the southeast and southwest of São Paulo, the extreme south of Minas Gerais and the southeast of Mato Grosso do Sul may have accumulated up to 50 mm above average, while the west of Mato Grosso do Sul should record volumes below expectations.

The South region is expected to experience the highest rainfall. The forecast points to above-average rainfall in virtually all states, with areas of Rio Grande do Sul standing out, with a potential increase in rainfall exceeding 200 mm in September.

Temperatures

Average temperatures are expected to be above the climatological average in the Northeast, Central-West, Southeast, and parts of the North. In the Northeast, temperatures range from 22°C to 27,5°C, but areas of Pernambuco and Bahia may record lows between 17°C and 20°C.

In the Southeast, temperatures are expected to exceed 15°C, with higher values ​​in central and western Minas Gerais. In the South, temperatures are close to average, except in Paraná, where positive anomalies could reach 0,6°C.

In the Center-West, the average is expected to exceed 22,5°C in practically all states, with the exception of southern Mato Grosso do Sul, where temperatures are expected to remain above 20°C.

Impacts on agriculture

According to Inmet, the climate scenario will have different effects on the country's main agricultural chains.

• North: The heat and near-normal rainfall favor permanent crops such as cocoa and açaí, but water replenishment tends to be limited in southwestern Pará, Roraima, and Acre, increasing the risk of water stress in crops and pastures.
• Northeast: Regular rains should benefit beans and corn, but areas in northern Bahia and Rio Grande do Norte may face water shortages, harming dryland crops and pastures.
• Midwest: Average rainfall and higher temperatures favor the harvest of second-season corn and cotton. However, for areas planting third-season soybeans and beans, heat combined with low humidity can compromise germination and grain filling, requiring greater water management.
• Southeast: Regular rainfall tends to benefit coffee and sugarcane harvests. However, heat can accelerate physiological processes and intensify evapotranspiration, requiring careful soil water management, especially in early soybean and corn crops.
• South: Excessive rain can make sowing difficult. On the other hand, crops already in development tend to benefit, such as sugarcane in Paraná.

Inmet emphasizes that producers must reinforce water management strategies and conservation practices to reduce risks due to the combination of high temperatures and irregular rainfall distribution in some regions.