A rare and powerful tornado hit parts of the Île-de-France region at 17:45 local time on Monday, October 20, producing severe local damage in the Val-d’Oise department, about 20 km (13 miles) north-east of Paris. The phenomenon lasted only a few minutes but was described by authorities as an event of “sudden and rare intensity.”
According to the Val-d’Oise prefecture and emergency services, one person was killed, a 23-year-old construction worker who was on site when several cranes collapsed. Nine others were injured, four of them in critical condition and five with lighter injuries.
The tornado caused significant destruction across several communes, including Ermont, Eaubonne, Franconville, and Sannois. At least three large cranes toppled at a construction site, crushing vehicles and damaging nearby buildings. Several vehicles were overturned, numerous roofs were torn off, trees were uprooted, and power lines were brought down, obstructing several local roads.
Meteorologists from Météo-France noted that strong convective activity was present across the Paris region that day, with local wind gusts exceeding 100 km/h (62 mph) likely within the tornado’s core.
The French severe-weather observatory Keraunos confirmed the tornado, though its final assessment, including path length, width, and wind speed, remains pending. Preliminary analysis indicates that the event was associated with a low-topped supercell, developing along a convergence line of humid air in unstable conditions over northern France.
Keraunos meteorologists reported a second tornado probably hit the Chaumont-en-Vexin area in Oise at the same time, with significantly less damage nonetheless.
According to the European Severe Weather Database (ESWD), managed by the European Severe Storms Laboratory (ESSL), the Ermont tornado has been provisionally classified as IF2 on the International Fujita (IF) scale, corresponding to estimated wind speeds of 180–220 km/h (112–137 mph).
The ESWD report lists multiple affected municipalities, Ermont, Eaubonne, Franconville, Argenteuil, Andilly, and Montmorency, and confirms one fatality and nine injuries, of which four are critical. The reported direction of movement was west-southwest to east-northeast (WSW–ENE).
The findings were filed by ESWD management team members Thilo Kühne and Igor Laskowski, along with observers Zhongjian Liang and Nicolas Baluteau, and are based on verified photographic and eyewitness damage documentation.
Independent meteorological analysis by Aramétéo France supports the ESWD findings, describing the event as the result of a supercell thunderstorm that formed over Yvelines around 17:00 LT before intensifying as it moved toward Val-d’Oise.
According to their assessment, the storm exhibited wind shear near 55 km/h (34 mph), providing conditions favorable for tornadogenesis. Aramétéo’s evaluation of debris orientation and structural destruction suggests winds near the upper range of EF-2, consistent with the IF2 classification reported by the European Severe Weather Database (ESWD).
Keraunos is expected to publish a full damage survey in the coming days, which will determine the tornado’s official rating, path length, and precise wind parameters once ground analysis is complete.
Local officials opened a municipal gymnasium in Ermont to accommodate residents displaced from damaged homes, and power outages affected approximately 1 700 households overnight.
The French Interior Minister Laurent Núñez described the episode as “brutal and extremely violent, though brief,” and expressed condolences to the victim’s family. Meteorological authorities have since launched a full survey to document the damage pattern and determine the tornado’s final classification.
Tornadoes of such intensity are uncommon in metropolitan France and particularly rare in the Île-de-France region.
The last event of this kind in Val-d’Oise occurred shortly before 18:00 LT on July 16, 2003, when a low-intensity EF1 tornado briefly touched down at Roissy–Charles-de-Gaulle Airport. The phenomenon remained on the ground for a short duration before dissipating in neighbouring Seine-et-Marne.
According to archived damage surveys, the 2003 event produced winds estimated between 135 and 175 km/h (84–109 mph) and affected the communes of Roissy-en-France and Mauregard. It tore off hangar panels, lifted several containers, one of which struck a parked aircraft, and displaced a 125 kg (275 pounds) cargo pallet.
According to climatological data, the Val-d’Oise department experiences wind speeds above 100 km/h (62 mph) on fewer than two days per year on average. France records about 20 tornadoes annually, most of which are within the IF0 to IF1 range, while deadly events remain exceptional. The last confirmed fatal tornado (3 fatalities) occurred in 2008.
References:
1 Tornade meurtrière dans le Val-d’Oise le 20 octobre – Keraunos – October 20, 2025
2 Tornade EF1 à Roissy-en-France (Val-d’Oise) le 16 juillet 2003 – Keraunos – Accessed on October 21, 2025