French weather agency, Météo France, has alerted the police about an alleged interference in the operation of an automated data processing system by Polymarket, a prediction market platform that offers sports-related wagers. The incident occurred on April 6 and 15 when temperature readings from a sensor near the Paris-Charles de Gaulle airport spiked by more than three degrees Celsius before returning to normal within minutes. One trader made $14,000 trading on a market linked to the sensor, while another account purchased shares on an 18°C outcome when odds were below 1%, and exited with around $21,000 within 30 minutes of the spike. The incidents expose a structural vulnerability in prediction markets that peg payouts to a single real-world data point, which could potentially be beneficial for forecasting applications such as energy demand. This incident is the second incident involving Polymarket in as many weeks.