Rio Bonito do Iguaçu tornado upgraded to EF-4, placing Brazil among sites of 2025’s most violent tornadoes worldwide

MetSul Meteorologia has released an updated post-event analysis of the tornado that devastated the municipality of Rio Bonito do Iguaçu in southern Brazil on November 7.

According to the report, damage indicators and the degree of destruction correspond to category EF-4 on the Enhanced Fujita Scale, implying winds of 250 km/h to 300 km/h (155 mph to 186 mph).

The tornado caused catastrophic damage across the city, flattening large sections of the urban area. More than half of all buildings were destroyed or severely damaged, and entire neighborhoods were reduced to rubble.

Local authorities reported six deaths and at least 437 people injured, while other official estimates cite more than 750 people treated for storm-related injuries. The municipality, home to roughly 14 000 residents, remains under emergency conditions.

According to MetSul, the Rio Bonito do Iguaçu tornado is the most intense and deadliest to strike Brazil in over two decades. Historical records show that the last comparable event occurred in 1959 in Palmas, Paraná, when an estimated F4 tornado killed 35 people. In terms of casualties, the 2025 event is the worst since the Antônio Prado tornado in Rio Grande do Sul in 2003.

MetSul compared the Rio Bonito do Iguaçu tornado with global statistics compiled by the United States National Oceanic and Atmospheric Administration (NOAA). By early November 2025, the United States had registered one EF-5 tornado, the first since 2013, and five EF-4 events. No EF-4 or EF-5 tornadoes were recorded this year in Europe or Canada.

This places the Paraná event among a small group of the planet’s strongest tornadoes in 2025.

Initial data released immediately after the disaster by Simepar (Sistema de Tecnologia e Monitoramento Ambiental do Paraná) indicated a maximum wind speed between 180 km/h and 250 km/h (110 mph to 155 mph), consistent with an F2 tornado on the original Fujita scale. The new assessment upgrades that classification substantially, based on extensive structural collapse, displacement of heavy vehicles, and complete leveling of reinforced masonry structures observed in post-storm imagery.

The storm developed in a highly unstable atmosphere produced by a strong temperature gradient between hot, humid air over northern Paraná and a cold front advancing from Argentina.

This combination generated supercell thunderstorms capable of producing severe downbursts and tornadoes. The temperature at the Entre Rios District station in Guarapuava reached 34.5°C (94.1°F) on November 7 — the highest November temperature on record at that site since observations began in 2001.

Emergency response and reconstruction efforts continue, with Civil Defense, firefighters, and local volunteers clearing debris and assisting displaced families. The Paraná state government declared a state of emergency, and the municipality is preparing to release an official donation channel for residents who lost their homes.

References:

¹ Tornado no Paraná está entre os mais intensos no planeta em 2025 – MetSul – November 10, 2025

Teo Blašković

I'm a dedicated researcher, journalist, and editor at The Watchers. With over 20 years of experience in the media industry, I specialize in hard science news, focusing on extreme weather, seismic and volcanic activity, space weather, and astronomy, including near-Earth objects and planetary defense strategies. You can reach me at teo /at/ watchers.news.

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