France’s national weather agency, Météo-France, is investigating whether temperature data in Paris was manipulated after suspicious spikes coincided with profitable bets on the cryptocurrency prediction market Polymarket. Agency data showed unusual temperature jumps at Charles de Gaulle Airport on April 6 and April 15, which Polymarket traders accurately wagered on, earning significant returns.
French meteorological authorities are investigating potential tampering after recording devices at Charles de Gaulle Airport registered dramatic evening temperature spikes on April 6 and April 15. “Based on physical findings regarding one of our instruments and an analysis of sensor data, Météo-France has indeed filed a complaint… regarding the tampering with an automated data processing system,” the agency confirmed.
The suspicious data precisely aligned with profitable bets on the cryptocurrency Polymarket platform. A user named Hoaqin won nearly $14,000 betting the temperature would reach 21°C on April 6. Another trader, Jiuzhou, turned $500 into over $3,000 on a similar April 15 bet.
Meteorologist Ruben Hallali noted the anomaly’s signature was highly unusual. “In 15 years of operational meteorology, that is not something weather does on its own,” said Hallali, whose company certifies weather data for insurance. He suggested a portable heat source near the sensor could cause such a spike without leaving an obvious trace.
This incident follows other Polymarket controversies, including a trader who won over $436,000 just hours before a reported capture of Venezuelan President Nicolás Maduro. These events have prompted lawmakers to draft bills aimed at regulating growing prediction markets. Polymarket did not immediately return a request for comment.
