An unprecedented heat wave places a quarter of Brazil's cities on extreme alert

Hundreds of cities are on high alert this week due to high temperatures due to the first major heat wave of the season, when there is more than a month left until the arrival of summer. An unprecedented wave in extension and duration. On the map of the National Institute of Meteorology (Inmet), two thirds of Brazil's territory appear painted orange and red, the colors for "danger" and "great danger." In this last category it is understood that there is a “high probability of damage and accidents, with risk to physical integrity or even human life,” according to the agency. A total of 1,413 municipalities in 13 states, among a total of about 5,000 municipalities, are in the risk zone, which is activated when temperatures reach five degrees above average for several consecutive days. Simultaneously, heavy rains are expected in the south.

The sweltering heat arrived a few days ago in a slow but steady growing up. In Rio de Janeiro over the weekend, crowds thronged the beaches seeking some relief, but the worst was yet to come. High humidity in the environment makes things worse. The degrees that the street thermometer markers show show numbers that even seem bearable compared to the feeling of someone walking under the scorching sun. On Monday, the mayor's office recorded a high of 42.5 degrees, but the actual wind chill was 50.5 degrees. In São Paulo it reached 37.4 degrees, the hottest day for the month of November in 19 years.

In addition to sweating, hot flashes and a bad mood, the heat wave is causing a race against time in search of air conditioning units and an explosion in energy demand, precisely due to the search for a cool breeze inside the home. According to the National Electrical System Operator (ONS), on Monday afternoon, at siesta time, the highest energy consumption in the history of Brazil occurred, 100,955 megawatts, the first time that the barrier of 100,000. The authorities of the sector also raised the forecast for energy consumption this November by 11% compared to last year.

In principle there should be no risk of blackouts because the dams are quite full (hydroelectric is Brazil's main source of energy), but it is a hypothesis that is not ruled out either. This Tuesday the power failed at several times in the Legislative Assembly of São Paulo, just when the deputies asked the electric company Enel for explanations about the historic blackout that the city experienced the previous week. A storm with wind gusts of more than 100 kilometers per hour toppled hundreds of trees and light poles and left hundreds of thousands of residents without electricity for days. Eight people died.

Heat waves in Brazil are becoming more frequent, as demonstrated by a study recently published by the Ministry of Science and Technology. The number of days a year with record temperatures has multiplied rapidly in 20 years. Between 1961 and 1990 it was something very exceptional, a maximum of seven days a year. Between 2011 and 2020, there was an average of 56 days of extreme heat.

The dry environment stimulates all kinds of environmental tragedies. The historic drought in the Amazon has dried up the rivers and left the city of Manaus in smoke due to fires. Something similar happens in The Pantanal, Brazil's other great natural treasure, an immense wetland that is the main refuge for jaguars in the world. So far in November, almost 2,400 fire outbreaks have already been detected here, five times more than the average.

But it's not just about heat, it's also about the increased frequency of associated extreme phenomena. The hot air blocks the instability and ends up raining a lot on the periphery of that hot mass. There are already warnings that record torrential rains may occur in the coming days, especially in southern Brazil. In some cities between 200 and 400 liters per square meter may fall, which will probably cause flooding, landslides and possibly deaths. In September, the passage of a cyclone in the state of Rio Grande do Sul caused 50 deaths and eight missing.