Polymarket Bets on Paris Temperature Prompt Investigation After Unusual Spikes

Early in April, Ruben Hallali got an unusual alert on his phone: The evening temperature at Paris Charles de Gaulle International Airport had jumped about 6 degrees Fahrenheit in seconds.

Mr. Hallali, the chief executive of the weather risk company Sereno, had set up notifications for extreme weather swings. Then, nine days later, it happened again.

“It was an isolated jump, at one single station, early in the evening,” said Mr. Hallali, who added that he noticed another strange coincidence about the spikes: The timing was just right for somebody to reap a windfall on the betting site Polymarket.

He wasn’t the only one who sensed a problem. Météo-France, the country’s national meteorological service, filed a complaint last week with the police and local prosecutors, saying it had evidence that a weather sensor at Charles de Gaulle, the country’s largest airport, may have been tampered with.

Article source: https://www.nytimes.com/2026/04/24/world/europe/polymarket-bets-france-paris-temperature-weather.html