Christmas Heat Wave Grips Southeast Brazil as São Paulo Sets December Record and Rio Hits 40.1°C

Overview

• Inmet’s orange-level alert remains in effect through December 26 for the entire Southeast and nearby areas of Paraná, Santa Catarina, Goiás and Mato Grosso do Sul.
• São Paulo reached 35.9°C at the Mirante de Santana station, the city’s highest December temperature on record and its hottest day of 2025.
• Rio de Janeiro hit 40.1°C at Alerta Rio’s Guaratiba station as the city holds at Calor 3, the third of five heat protocol levels with multi-day persistence expected.
• Rio’s state health authority warned all 92 municipalities of excessive heat, with 22 classified from mild to extreme risk and guidance to open hydration and cooling points.
• Holiday impacts included crowded beaches, 15 shoreline spots deemed unfit for bathing by Inea, and water-supply pressure reductions reported in Greater São Paulo as forecasters expect the heat to persist for several days.