São Paulo Civil Defense Issues Four-Day Storm Alert Amidst Ongoing Power Crisis

State Under Alert for Intense Rainfall and Strong Winds

The Civil Defense of São Paulo has issued a comprehensive alert for four days of intense rain and a high risk of disruptions across the state, commencing on Saturday, December 13th, and extending through Tuesday, December 16th, 2025. The warning highlights the potential for significant weather-related incidents as a slow-moving cold front traverses the Paulista territory.

This alert follows a period of severe weather, including an extratropical cyclone earlier in the week, which left millions of residents without electricity. The ongoing power crisis, with hundreds of thousands still affected, adds a layer of complexity to the current storm threat.

Detailed Weather Outlook and Potential Impacts

The forecast predicts persistent and, at times, intense rainfall, accompanied by lightning, strong wind gusts, and the possibility of hail. Wind speeds could reach up to 60 km/h, with some reports indicating gusts of up to 90 km/h or even 98 km/h in certain areas.

The primary concerns include:

• Flooding and flash floods: Especially in vulnerable urban areas.
• Landslides: Increased risk due to saturated soil.
• Other disruptions: Such as fallen trees and power outages.

For the capital, São Paulo, up to 50 millimeters of rain are expected on Saturday, with an additional 25 millimeters on Sunday. These combined totals represent approximately one-third of the average rainfall for the entire month of December.

Regions at High Risk and Lingering Challenges

The instability is expected to affect various parts of the state differently over the four-day period:

• Saturday, December 13th: The southern, central, and eastern regions of the state are anticipated to experience the most intense instability and highest accumulated rainfall.
• Sunday, December 14th: The cold front is projected to remain nearly stationary near the Paulista coast, leading to continuous rain and increasing the risk of landslides and floods as the soil becomes more saturated.
• Monday, December 15th: Rain will persist in several regions as the system slowly moves towards Rio de Janeiro, maintaining elevated risk levels.

Regions specifically identified for potentially high accumulated volumes include: Presidente Prudente, Marília, Bauru, Araraquara, Campinas, Sorocaba, Itapeva, Registro, Baixada Santista, Vale do Paraíba, Serra da Mantiqueira, Litoral Norte, the Metropolitan Region of São Paulo, Ribeirão Preto, Franca, and Barretos.

The current alert compounds challenges from a previous extratropical cyclone that caused widespread power outages, affecting over 2 million customers initially. As of December 13th, hundreds of thousands still faced electricity disruptions, leading to estimated losses of up to R$100 million for businesses in the hotel, restaurant, and bar sectors.

Safety Recommendations from Authorities

The São Paulo Civil Defense, in conjunction with the Public Ministry of São Paulo (MPSP) and the Center for Weather Forecasting and Climate Studies (CGE), urges residents to exercise extreme caution. Key safety recommendations include:

• Monitoring official warnings and updates.
• Avoiding proximity to metal objects in public spaces, such as poles and railings.
• Staying away from fallen power lines.
• Refraining from using plugged-in appliances and, if possible, disconnecting electronics to mitigate risks.
• Keeping doors and windows closed and avoiding outdoor areas during storms.
• Seeking safe shelter, away from trees and metallic structures.
• Never parking vehicles under trees.
• Absolutely avoiding crossing flooded streets, whether on foot or by car.

In case of emergencies, residents are advised to contact emergency services by dialing 199 or 193.