Unusual heat wave raises temperatures and dries air in São Paulo

São Paulo’s capital and much of the state are experiencing atypical heat and dry conditions due to a strong heat wave that will last until Monday (31). The hot, dry air mass over the central region of the country raises temperatures and drives down relative humidity. This weather pattern triggers health alerts and fire‑risk warnings in several cities across São Paulo.

Heat wave pushes temperatures up in the capital

On Sunday (30), São Paulo recorded temperatures ranging from 20 °C to 32 °C, with a muggy feel and sun breaking through clouds. The same pattern is expected on Monday (31), when thermometers may exceed 32 °C. Relative humidity in the capital should hover around 30 % in the afternoon, with no rain forecast for Greater São Paulo despite increasing cloudiness caused by a sea breeze arriving later in the day. So far, August has accumulated 27.9 mm of rain in the capital, representing 93.9 % of the 29.7 mm expected for the period.

Civil Defense warns of low humidity inland

In the interior, the drought situation is even more severe. The state Civil Defense issued an alert for critical relative humidity levels, which could drop below 12 % in areas such as Ribeirão Preto, Franca, Barretos, São José do Rio Preto and Araçatuba. The National Institute of Meteorology (Inmet) warns that low humidity raises the risk of forest fires and can cause health problems such as dry skin and discomfort in the eyes, mouth and nose.

Inmet yellow alert signals storm risk

Despite the predominance of dry weather, Inmet released a yellow alert indicating the possibility of thunderstorms in parts of São Paulo, Paraná, Santa Catarina, Mato Grosso do Sul, Minas Gerais, Rio de Janeiro and Mato Grosso. Along the border between São Paulo and Paraná, isolated rain is forecast for the late afternoon of Sunday (30).

Climatic instability causes deaths in the South

While the Southeast deals with heat, the South is facing strong climatic instability. Since Thursday (27), thunderstorms with hail have caused two deaths in the region. Unstable weather is expected to continue on Sunday (30) and Monday (31), with the risk of further hail in western and southern Paraná, central‑west Santa Catarina and northern and north‑west Rio Grande do Sul.

With information from Folha de S.Paulo, VEJA.