French police are investigating allegations of tampering with national weather forecasting service equipment at Paris Charles de Gaulle airport. The probe was launched after Météo-France flagged unusual temperature readings that coincided with suspicious winning bets placed on the prediction market Polymarket.
The anomalies occurred on the evenings of April 6 and April 15, when a sensor at the airport recorded abnormal temperature spikes. This data was used to settle wagers on the temperature in Paris for March and the first weeks of April.
Authorities suspect the sensor was compromised to influence betting outcomes, as one mystery trader earned $21,000 from the temperature spike. The case was referred to police after the forecasting office detected the suspicious readings alongside heavy betting activity.
These events come as weather betting has boomed on prediction markets such as Polymarket and Kalshi.