Inmet: weather forecast between August 25th and 31th, 2025

The National Institute of Meteorology (INMET) forecasts concentrated rainfall in isolated areas of the country between August 25 and 31, while much of the country is expected to experience dry weather and a drop in relative humidity. According to Meteorological Bulletin No. 32/2025, the highest rainfall accumulations, up to 60 mm, are expected in northern Amazonas and Amapá, while regions in the Central-West and Northeast regions will face drought conditions, with relative humidity potentially falling below 30%.

In the North Region, areas of instability are expected to be concentrated in the far north of Amazonas and central Amapá, with rainfall volumes that could exceed 50 mm (yellow and orange tones in Figure 1). The highest rainfall accumulations, around 60 mm, are forecast for central and northern Amapá and Amazonas. In contrast, in south-central Pará, Tocantins, Rondônia, eastern Acre, and southern Amazonas, no rain is forecast throughout the week. In these areas, relative humidity is expected to decrease, potentially reaching levels below 30%, as shown in Figure 2.

In much of the interior of the Northeast Region, no rain is forecast, with reduced relative humidity, especially in the southern portion of Maranhão, central Piauí, eastern Ceará, western Rio Grande do Norte, Paraíba, and Bahia, where values ​​​​may fall below 30% (Figure 2). In small areas of the Northeast coast, rainfall volumes below 10 mm are forecast (blue tones in Figure 1).

In the Central-West region, the forecast is for stable weather, that is, no rain in practically all states (white areas in Figure 1), with the exception of southern Mato Grosso do Sul, where accumulations of up to 10 mm are expected in the coming days (blue shades in Figure 1). Also noteworthy is the forecast for relative humidity below 30% throughout the region for the coming days, especially in north-central Mato Grosso (Figure 2).

Regarding the Southeast region, the forecast indicates no rain for most of Minas Gerais (except for the extreme south of the state) and north-central São Paulo (white areas in Figure 1). Larger volumes of up to 40 mm are forecast for the extreme south of São Paulo (green shades in Figure 1), while for the east of the state, as well as most of Rio de Janeiro and Espírito Santo, accumulated amounts of up to 10 mm are forecast (blue shades in Figure 1). Also noteworthy is the relative humidity below 30% forecast for the coming days in the Triângulo Mineiro and north-central São Paulo regions (Figure 2).

For the Southern Region, rainfall accumulations of up to 50 mm are forecast in west-central Paraná, most of Santa Catarina, and the Southwest Rio Grande do Sul mesoregion (green and yellow tones in Figure 1), resulting from the action of a trough in the region. For other sectors, such as north-central Paraná and the mesoregions of East-Central and Northwest Rio Grande do Sul, volumes of up to 20 mm are forecast in the coming days (blue and gray tones in Figure 1). Also noteworthy is the low relative humidity below 30% forecast for northern Paraná (Figure 2).