Users of the Polymarket betting platform have won large sums betting on unusual temperatures in Paris. Météo France is investigating possible data manipulation.

On April 6, two users of the Polymarket betting platform won significant amounts by betting on an unusual maximum temperature of 21°C in Paris, and one of them earned nearly $14,000 from a bet of under $30. This situation sparked controversy, as the temperature suddenly rose by 4-5 degrees in a matter of minutes, and meteorologists consider such variations to be extremely unlikely.

Météo France filed a complaint to investigate possible manipulation of the weather data system, essential for flight safety. On April 15, another sudden increase in temperature led to a 95% probability on the betting market, raising suspicions. Polymarket subsequently changed the reference sensor for weather forecasts in Paris, but concerns about market manipulation and the use of insider information continue to grow.