Forecast for December indicates irregular rainfall in Brazil

The forecast from the National Institute of Meteorology (Inmet) for the month of December indicates rainfall between the climatological average (gray tone) and above average (blue tone) in much of the North Region, in the northeast of Mato Grosso, in São Paulo, in the south of Minas Gerais and in the west of Piauí (Figure 1a). On the other hand, the South Region should register below average precipitation (yellow tone), with the exception of areas located in the east of Santa Catarina and north of Paraná, where accumulations may be normal or above average (blue tones). 

In the central-eastern part of the Northeast Region, the forecast indicates normal rainfall, except in areas of Bahia, Maranhão and southern Piauí, where rainfall volumes are expected to be below the climatological average, with volumes below 200 mm. In the central-northern parts of Minas Gerais, Espírito Santo, Goiás and Mato Grosso do Sul, rainfall is expected to vary between close to and below the historical average, as represented by the gray and yellow tones on the map in Figure 1a.

Considering Inmet's climate forecast for December 2024 and its possible impacts on the main crops, the forecast for more regular and well-distributed rainfall will continue to occur in the production areas of the North region, favoring sowing and crop development. In Matopiba (a region that encompasses the states of Maranhão, Tocantins, Piauí and Bahia), the forecast points to lower volumes of rainfall, but they will be sufficient to maintain soil moisture in most locations.

In most of the Central-West and Southeast regions, December will be marked by higher soil moisture levels, due to the forecast of more regular rainfall that will favor the development of first-crop crops. Some areas may be affected by poor rainfall distribution, such as southwest Mato Grosso, south Mato Grosso do Sul, west São Paulo and north Minas Gerais. 

In much of the South Region, rainfall is expected to be close to the historical average and soil moisture levels will remain high, benefiting sowing and the development of first-season crops. Some areas in southern Rio Grande do Sul and northwest Paraná may experience lower rainfall volumes and reduced soil moisture.

Temperature

As for temperatures, the forecast indicates that they should be above average in much of the country (yellow and orange tones on the map in Figure 1b), with the possibility of some days of excessive heat (red tones), mainly in the north of the country, where average air temperatures can exceed 28ºC. 

In specific areas of Amazonas, Amapá, southwest Paraná, east of Santa Catarina and south of Rio Grande do Sul, temperatures close to or slightly below average are expected (gray and blue tones on the map in Figure 1b), due to the occurrence of consecutive days with rain that can alleviate the temperature.