Two accounts on the prediction market platform Polymarket have raised suspicions after earning $37,000 from correctly betting on anomalous temperature spikes at Paris’s Charles de Gaulle Airport. French media reported the temperature readings suddenly climbed and fell on April 6 and 15, coinciding with profitable trades. Blockchain analytics noted the spikes were not reflected at nearby stations, and one winning account is under 30 days old, prompting allegations of potential sensor tampering. Météo France, the national weather service, has reportedly filed a police complaint.
Two accounts on the crypto-based prediction market Polymarket have drawn scrutiny after profiting $37,000 from bets on unusual temperature readings in France. The markets focused on the highest daily temperature at Paris Charles de Gaulle Airport on April 6 and April 15.
On April 6, the temperature reportedly suddenly climbed over 21 degrees Celsius before immediately dropping again. The winning account, which is under 30 days old, took over $16,000 from that market.
A similar anomaly occurred on April 15, according to blockchain analytics tool Bubblemaps. The station showed 18 degrees Celsius most of the day, then suddenly spiked to 22 degrees before dropping back.
“That spike didn’t show on nearby stations,” Bubblemaps analysts stated. Just before the spike, one trader began buying shares betting against the 18°C reading before exiting with over $21,000.
The winning trader account has been highly active on Polymarket with wagers on crypto and weather. This $21,000 payout is its largest by a wide margin; its next highest is only $13.
Ruben Hallali, a meteorologist, told French media the glitch was unlikely natural. “Such temperature variations seem very unlikely, especially on these two dates, and over such a short period,” he said.
“We can imagine that an individual with a good understanding of how the sensors work intervened, resulting in temperatures rising by two degrees at the right time, to validate a bet,” Hallali added.
Météo France, the official government weather agency, has reportedly made a complaint with the Roissy Air Transport Gendarmerie Brigade. The complaint alleges tampering with the operation of its automated data processing systems.
