São Paulo State Braces for Week-Long Warm Spell With Temperatures Up to 5°C Above Average

The state of São Paulo is set to experience a warm spell, known as 'veranico', starting Friday, November 17th, and lasting until Friday, November 24th. During this period, temperatures are predicted to be 3°C to 5°C higher than the seasonal average, affecting nearly the entire state. The only exception is the border region with Paraná, including the southern Vale do Ribeira, where the phenomenon's influence will be less pronounced. Inland areas of São Paulo could see afternoon temperatures exceeding 30°C. Meteorologist César Soares from Climatempo explained that 'veranico' is a warm period within a colder season, distinct from a heatwave which requires temperatures at least 5°C above average for five consecutive days. This warm spell is attributed to an atmospheric block caused by a large mass of dry air over central Brazil, preventing the advance of cold air masses and leading to temperature increases. The dry air also results in clear skies, allowing daytime heat to dissipate quickly at night, causing colder mornings and a wider diurnal temperature range. Consequently, despite warm afternoons, early mornings remain cool. The dry air mass also significantly reduces relative humidity, especially in the afternoons. Residents are advised to stay hydrated, avoid strenuous activities during the hottest parts of the day, and use humidifiers or damp cloths to moisten indoor environments during the afternoon. However, this should be avoided at night when natural humidity increases, preventing mold growth. Temperature variations will occur across regions, with coastal areas experiencing less heat due to oceanic influence, while inland and valley regions may be hotter. Higher altitude areas are expected to remain milder. While 'veranico' is a natural winter phenomenon in Brazil, climate change may increase its frequency and intensity.