French authorities are investigating allegations that a temperature sensor at Paris Charles de Gaulle airport was deliberately tampered with, enabling a bettor to win $34,000 (£25,100) on the prediction market Polymarket. The probe was launched after unusual temperature spikes were recorded on two separate days in April, coinciding with large wagers placed on the platform.
Investigation details
Météo-France, the national meteorological service, filed a complaint with the Air Transport Gendarmerie Brigade of Roissy after detecting anomalies in sensor data. A spokesperson confirmed: “In view of physical findings on one of our instruments and the analysis of sensor data, Météo-France was indeed led to file a complaint for alteration of the operation of an automated data processing system.” The agency declined further comment to avoid compromising the ongoing investigation.
Temperature anomalies
On 6 April and 15 April, the sensor recorded peak temperatures significantly higher than expected. At 7pm on the first date, a reading of 21°C was noted, while on 15 April, 22°C was recorded at 9:30pm. The probability of temperatures exceeding 18°C on both days was estimated at just 1%, meaning a successful bet would yield substantial returns. One trader won $21,000 on 15 April, contributing to the total $34,000 payout.
Reports from crypto outlets and trader publications speculated that a battery-powered hairdryer might have been used to artificially raise the temperature reading, though these claims remain unverified. Weather forums suggested such a device could have been employed, according to French newspaper Le Monde.
Shift in data source
Following the incident, the data source for Paris’s highest temperature has been moved to Paris-Le Bourget airport, as reported by The Telegraph. Sébastien Brana, an administrator of the Infoclimat Association, noted: “There was work done on the station's shelter yesterday that led to these aberrant readings.” Initially, the anomaly was attributed to a “sensor drift” or “maintenance problem,” but suspicions were raised internally. “We reported these suspicions internally to Météo France, and the least we can say is that our report was taken very seriously and at a high level, resulting in a formal complaint being filed,” Brana added.
Polymarket controversy
Polymarket, the world’s largest prediction market, has faced previous accusations of enabling insider trading. The platform allows bets on a wide array of topics, from sports and weather to geopolitical events like the war in Iran. Earlier this month, it was forced to remove a bet on the fate of a US pilot missing in Iran after critics labelled it a “dystopian death market.” The Independent has contacted Polymarket for comment regarding the weather sensor tampering allegations.
