A low-angle view of the Eiffel Tower, partially framed by flowering branches below a blue sky dotted with clouds in Paris, France, on April 10, 2026.
Riccardo Milani/AFP through Getty Photographs
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Riccardo Milani/AFP through Getty Photographs
A hair dryer? A lighter? A fortunate coincidence?
Authorities in France are investigating attainable tampering with a climate monitoring system at Charles de Gaulle Airport in Paris after an uncommon temperature spike was recorded across the identical time a Polymarket dealer cashed in.
An nameless dealer with the username “xX25Xx” has drawn scrutiny from analysts and fellow merchants on Polymarket, the place individuals can guess on issues like a metropolis’s prime temperature and different real-world occasions.
The dealer guess $119 that the climate in Paris on April 15 would leap previous the equal of 64 levels Fahrenheit, and climate fanatics on-line observed a sudden spike in temperature on that day. Because of the sudden rise in temperature, the dealer netted $21,398 in revenue.
The Polymarket dealer’s bets earlier than they deleted their account. Accessed through the WayBack Machine.
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When native meteorologists dominated out that the temperature anomaly had occurred naturally, the Polymarket dealer deleted their account.
The French climate service, Météo-France, mentioned it filed a criticism with airport police about attainable tampering with its tools, French broadcaster BFM TV reported.
Météo-France and the airport police didn’t reply to NPR’s request for remark.
Whereas authorities in Paris are nonetheless investigating what occurred, climate watchers and Polymarket merchants on on-line boards have raised two prospects for the way the temperature may have been raised: a lighter or a battery-powered hairdryer.
The anomalous climate spike in comparison with one other climate sensor in Paris.
Bubblemaps
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Bubblemaps
“Like it!” wrote a Discord consumer who goes by Vince, who often trades on climate on Polymarket. “I’ve bought to have a type of cordless hair dryers with a twine that connects to a climate station!”
One other consumer referred to as Sakuku on Discord quipped: “The great outdated ‘blowdrier with warmth setting on the publicly-accessible climate monitoring station close to the airport’ rip-off,” they wrote. “It is a traditional.”
An evaluation by the French analytics agency Bubblemaps discovered that no different climate station within the space recorded the temperature spike, and that the successful guess from the Polymarket dealer in query was 20 instances bigger than their typical wager.
Polymarket didn’t return a request for remark.
Prediction markets like Polymarket and Kalshi enable individuals to place bets on each side of recent life, from what phrases President Trump will utter to the timing of navy strikes in Iran and the result of elections.
Because the websites have exploded in reputation, tales have circulated of merchants going to extraordinary lengths to search out an edge, like standing exterior of the Tremendous Bowl stadium to file the size of the nationwide anthem and searching by means of the software program code of a musician’s web site to seek for file sale bulletins that aren’t but public.
There even have been a number of high-profile situations of suspected insider buying and selling, like when a dealer made greater than $500,000 betting on the ousting of Venezuela’s President Nicolas Maduro and the precise timing an Iran ceasefire can be introduced. Going again additional, prediction market analysts have recognized a dealer who seems to have profited handsomely from having advance data of the pardons former President Biden granted in his ultimate hours in workplace.
Within the face of what seems to be the abuse and manipulation of those prediction markets, lawmakers have proposed a flurry of actions to rein within the websites and dozens of states have launched lawsuits aiming to have the apps regulated as playing companies.
Proper now, the Commodity Futures Buying and selling Fee oversees the business, with the Trump administration embracing a light-touch method to the norm-busting corporations.
The French climate guess occurred on Polymarket’s unregulated abroad alternate, which is simply accessible by U.S. merchants with a digital personal community.
Polymarket’s web site exhibits it’s now not counting on the Charles de Gaulle climate sensor information and is as an alternative utilizing information from a tool on the Paris–Le Bourget Airport to settle bets.
