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Rainfall in April was above average in the Midwest and Southeast

Significant volumes were observed in the state of Rio de Janeiro

08.05.2025 | 15:03 (UTC -3)

inmet

In April, rainfall was significant in the North and Northeast regions of the country, but within normal limits. However, the highlight was the Central-West and Southeast regions, where some cities recorded volumes above the climatological average for the period, such as Teresópolis, in Rio de Janeiro, which totaled 689,4 mm when the normal is 106,3 mm, representing an increase of 548% (Table 1).

Figure 1 - map of accumulated precipitation (mm) in the last 30 days of April (rainiest areas in dark blue and the variation in colors indicates a reduction in the volume of rain that changes to light blue, dark green and light to orange and yellow tones)

The data is part of the technical note Extreme Events from the National Institute of Meteorology (Inmet), released today (8/5), which shows the main meteorological phenomena that affected Brazil in April 2025.

In the North Region, the highest accumulations were recorded in the western portion of Amazonas, eastern Acre, extreme northern Amapá and northeastern Pará with totals above 300 mm. While in the Northeast Region, the highlights are the northern parts of Maranhão and Piauí, with volumes above 200 mm.

In the Central-West and Southeast regions, volumes were above 150 mm, mainly in a large part of Mato Grosso and Mato Grosso do Sul, southern Goiás and the coast of the Southeast region, with more voluminous rainfall in the state of Rio de Janeiro.

In the southern region of the country, rainfall volumes exceeded 60 mm, but in specific areas, such as the extreme south and coast of Rio Grande do Sul, as well as the northwest of Paraná, the accumulated amounts exceeded 150 mm.

Table 1 – total accumulated precipitation in April 2025 indicating the largest deviations (positive in blue) in Teresópolis (RJ), Salinas (MG) and Cuiabá (MT); the smallest deviations (negative in red) in São Luiz Gonzaga (RS), Palmas (TO) and Natal (RN)

Temperature

In addition to the significant rainfall accumulations that occurred in some regions of Brazil, the month of April was also marked by intense heat in the Northeast Region, with days in which maximum temperatures exceeded 38°C. The highest temperatures were observed in locations in the states of Piauí, Alagoas, Rio Grande do Norte, Bahia and Paraíba.

However, when comparing the maximum temperatures of April 2025 with historical records, it was found that most municipalities did not exceed the extreme values recorded in previous years. The exception was the meteorological station of São João do Piauí (PI), which reached 40,0°C on 09/04, surpassing the previous record of 39,6°C, recorded in 1998.

Figure 2: Comparison of the Maximum Temperature (°C) of April 2025 (light orange) and April of the last record in the historical series (dark orange)

The cold was also constant in the south of Mato Grosso do Sul and in the southern region of the country due to the entry of a cold air mass between the 29th and 30th of April, causing temperatures to drop in these areas.

On April 29, negative anomalies in minimum temperatures were observed, with values up to 04°C below average. As a result, minimum temperatures below 5°C were recorded in several locations, especially in the South Region. The meteorological stations of General Carneiro (RS), Vacaria (RS) and São Joaquim (SC) stand out, as they woke up with minimum temperatures of -5°C, 0,1°C and 2,8°C, respectively (Table 3,1).