October: what to expect from the weather in Brazil

The National Institute of Meteorology (INMET) projects October to be marked by highly variable rainfall and above-average heat across much of Brazil. Temperatures are expected to range between 22°C and 32°C, while the gradual return of rains is expected to impact different regions unevenly, impacting crop yields and water availability for pastures.

Na Northern Region, most of Pará, central Tocantins, and areas of Amazonas are expected to experience below-average rainfall, with deficits of up to 50 mm. Amapá, the extreme north of Pará, western Acre, northern Rondônia, and the border regions between Amazonas, Peru, and Colombia are expected to experience above-average rainfall, while other areas are expected to remain close to expected climatological values. Northeastern Pará and Tocantins may experience highs between 27°C and 32°C, up to 1,5°C above the historical average.

No NortheastRainfall is expected to remain near average in almost all states, with the exception of northern Bahia, southern Maranhão, and Piauí, which may experience higher-than-expected rainfall. Temperatures throughout the state are expected to remain above average, particularly in western Bahia, southern Maranhão, and Piauí, where temperatures could exceed 28°C. Even in areas near the coast, temperatures are expected to remain high, between 26°C and 28°C.

A Midwest region Below-average rainfall is expected across much of Mato Grosso, northwestern Goiás, and the Federal District, while western and southernmost Mato Grosso and central-eastern Mato Grosso do Sul may experience above-average rainfall. Temperatures are expected to remain above normal across virtually the entire region, with highs exceeding 28°C in northern and eastern Mato Grosso and western Mato Grosso do Sul.

No SoutheastMinas Gerais, parts of São Paulo, and almost all of Rio de Janeiro are expected to experience above-average rainfall, while the rest of the region is expected to experience rainfall close to the historical average. Temperatures are expected to exceed 22°C, with highs exceeding 25°C in areas of central-western Minas Gerais and São Paulo.

Na South, Paraná and areas in the north and west of Santa Catarina are expected to experience above-average rainfall, favoring soil moisture for crops such as soybeans. In contrast, Rio Grande do Sul is expected to experience below-average rainfall, with deficits of up to 75 mm in some regions. Temperatures are expected to be below average in the center of the state, with highs below 20°C, while in the north and east of Paraná, highs of up to 1°C are expected, with highs above 24°C.

Impacts on agricultural crops

For agriculture, the October climate scenario brings varied impacts. Northern Region, water deficit can compromise fruiting and the weight of cocoa, açaí, and other permanent crops, while areas with above-average rainfall will have better conditions for agricultural development and pastures. 

No Northeast, the near-average rainfall regime favors grain filling in bean and corn crops, although the intense heat requires attention to irrigation management, especially in dryland areas. 

Na Midwest region, the weather should benefit the harvest of second-crop corn and cotton, but the lack of rainfall in some areas could compromise summer crops being planted. 

No Southeast, water availability favors the vegetative growth of crops such as coffee and sugar cane and contributes to the beginning of the planting of summer crops. 

Now at Sul, below-average rainfall in Rio Grande do Sul and lower temperatures benefit winter crops such as wheat, oats, barley and canola, while areas of Santa Catarina and Paraná can take advantage of soil moisture for sowing soybeans.