# Extreme rainfall and flooding in São Paulo

> Live situation record from CLSTR: https://clstr.news/situations/extreme-rainfall-and-flooding-in-so-paulo
> Updated: 2026-09-22T23:05:43.000Z. Sources: 40. Developments: 2.

São Paulo has recorded its heaviest rainfall in 83 years, with the Mirante de Santana station reaching 304.6 mm of accumulated rain by late Tuesday. This volume surpasses the historical January average of 292 mm and nearly quadruples the typical September average of 83.3 mm.

The extreme precipitation, initially attributed to the El Niño phenomenon, was driven by a cold front combined with a polar air mass. The weather has caused widespread disruption, including flooding, landslides, and structural damage. Fatalities and missing persons have been reported, including multiple deaths following the collapse of an embargoed 12-story residential building in the Penha neighborhood. In the Vale do Ribeira region, rising river levels forced 152 families into shelters.

While weather conditions are expected to stabilize with sun and rising temperatures by the end of the week, meteorological projections suggest the state will continue to see above-average rainfall throughout the spring season. 

The heavy rains have also significantly impacted consumer behavior. Data from Shopee indicates a surge in demand for rain-related products compared to August, including a 380% increase in searches for silicone shoe covers, a 290% increase for pet raincoats, and a 220% rise in searches for clothes dryers. Sales of umbrellas and raincoats also increased by more than 250%.

## Claims

- Heavy rains in the state of São Paulo have resulted in at least eight deaths and one person missing. (disputed by 2 sources)
- The city of São Paulo recorded 253.8 mm of accumulated rain at the Mirante de Santana station by Monday morning. (corroborated by 18 sources)
- September is the rainiest month in the city of São Paulo since records began in 1943. (corroborated by 18 sources)
- The El Niño phenomenon is responsible for the intense rainfall in the state of São Paulo. (corroborated by 5 sources)
- The Ribeira de Iguape River rose nearly nine meters, forcing 54 families to evacuate. (corroborated by 3 sources)
- A 12-story residential building under construction collapsed in São Paulo; the site had been embargoed since 2021. (corroborated by 2 sources)
- Rainfall in September has increased the level of São Paulo's reservoirs by 9%. (corroborated by 2 sources)
- Cemaden has issued 60 alerts for high and moderate risks of landslides, flooding, and inundation in São Paulo. (corroborated by 2 sources)

## Timeline

### 2026-09-22: São Paulo records highest September rainfall in 83 years

São Paulo recorded its highest September rainfall in 83 years, surpassing January averages. The extreme weather has triggered a massive surge in consumer demand for umbrellas, raincoats, and dryers.

5 sources. https://clstr.news/cluster/so-paulo-records-highest-september-rainfall-in-83-years

### 2026-09-14: São Paulo records highest September rainfall since 1943

São Paulo has recorded its rainiest September since 1943, with rainfall volumes three times the monthly average. The extreme weather, linked to El Niño, has caused multiple deaths and widespread flooding.

37 sources. https://clstr.news/cluster/so-paulo-storms-cause-deaths-and-flooding

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Cite as: Extreme rainfall and flooding in São Paulo. CLSTR, https://clstr.news/situations/extreme-rainfall-and-flooding-in-so-paulo