Summer kicks off in Brazil, heat likely to top historical average
It’s already summer in Brazil. More precisely, it has been since 0:27 am this Friday (Dec. 22), when the season arrived in the entire Southern Hemisphere. After a year marked by atypical heat waves, temperatures should rise above the historical average, according to a climate report by the National Institute of Meteorology (Inmet), in partnership with the National Institute for Space Research (Inpe).
Normally, Brazilians summers are marked by rising temperatures, longer days than nights, heavy rainfall, electrical discharges, and moderate to strong winds. Due to the El Niño phenomenon, which shifts the distribution of water temperatures in the Pacific Ocean, changes in the climate are likely to be more intense. In Brazil, the effects of El Niño may last throughout the season, which ends on March 20, 2024.
From January to March, Brazil's Northeast could record heat of 1ºC above the historical average. Regarding rainfall, the states of Acre, Roraima, Amapá, and the southwest of Amazonas should see volumes close to or above average in the quarter. Other regions should continue to face a period of drought. This is the case for most of Amazonas, Pará, Rondônia, and Tocantins.
The Northeast is also expecting above-average temperatures, especially in the states of Maranhão, Piauí, and northern Bahia. Rainfall is expected to be close to or below climatology in the center-north of the region. In the center-south, on the other hand, due to the pattern of warmer waters in the South Atlantic, there may be more voluminous precipitation.
In the Central-West, strong heat should be the trend across all states, with values above 1ºC of the historical average. Rains are also expected to be close to or above average in virtually the entire region, except in the west of Mato Grosso, which should see a volume slightly below its climatology for the quarter.
In the Southeast, temperatures are likely to be high in all states, with forecasts above the average by 0.5ºC. More rain is expected, especially in Minas Gerais, where it may be more frequent, as well as more intense.
In the South, heat close to or slightly above normal is expected in Paraná, Santa Catarina, and northern Rio Grande do Sul. In the other areas of the last state, average or below-average temperatures are possible. Rainfall should be heavier in Rio Grande do Sul, especially in the southern part of the state. Elsewhere in the region, showers will be irregular, with totals close to or just below average.
The impact on the harvest
The institute draws attention to the impacts of El Niño on the 2023–24 summer harvest. In the states of Maranhão, Tocantins, Piauí, and Bahia, rainfall was below average in October and November. As a result, soil water levels are quite low, which is not favorable to the early stages of summer crops. Levels should remain low in the coming months, with a water deficit and increased evapotranspiration due to the high temperatures.
In Central Brazil, an increase in water levels was observed in the soil in some locations, due to the return of rain late in December. With the exception of the north of Minas Gerais, the scenario was favorable for the resumption of planting to develop first-crop crops.
For the South, the predicted rainfall volumes should keep water levels in the soil high, but the probability of a water surplus is lower in some locations. With the decrease in rainfall compared to previous months, the sowing of first-crop crops in regions that are behind schedule is likely to be resumed.
