Brazil: High temperatures forecast to persist across central, southeastern, and western regions through at least May 10 /update 1

Forecast models indicate that high temperatures will persist across parts of central, southeastern, and western Brazil through at least May 10. Temperatures up to 38 C (100 F) are possible across parts of the affected region and many areas will see persistent temperatures of more than 5 C (9 F) above the average for the time of year.

As of May 1, the National Institute of Meteorology (INMET) has issued the following warnings across the affected area:

• Orange heatwave warnings (the middle level on a three-tier scale): Across Mato Grosso do Sul and Rio de Janeiro states and parts of southwestern Goias, southern Mato Grosso, southwestern Minas Gerais, northern Parana, and northwestern Sao Paulo states.

• Yellow heatwave warnings: Across the rest of Sao Paulo State and parts of southern Minas Gerais State.

Officials could upgrade or expand the alerts as the heatwave develops over the coming days.

The high temperatures may result in increased energy and water demand and a heightened risk of heat-related illnesses, such as heat exhaustion and heat stroke.

The extended period of oppressive heat and dry conditions may produce ideal circumstances for wildfire growth throughout the affected areas. Heatwaves also pose a threat to vulnerable groups - such as the elderly, children, pregnant women, and those with respiratory illnesses - due to the increased possibility of heat stroke or heat exhaustion during prolonged exposure to high temperatures. These health risks could also extend to relatively healthy individuals during significant heatwave events. In addition to significantly impacting athletes and those who work outdoors, high temperatures can cause problems for people using mass transit. The lack of air conditioning and cramped vehicles during rush hour may lead to some passengers being hospitalized for dehydration.

Very high temperatures may warp rail tracks and force passenger and freight trains to operate at reduced speeds. Road surface damage is also possible, and overheated vehicles may worsen traffic problems in urban areas where congestion is already a problem. Commercial trucking disruptions might occur, as very high temperatures put more stress on vehicles, making tire blowouts more common. Major flight disruptions are unlikely at regional airports, but general aviation disruptions are possible, and some airfreight carriers could reduce cargo loads. High temperatures could lead to an increased demand for electricity, which might trigger localized brownouts or blackouts, exacerbating hazardous conditions when air conditioning is no longer possible.