'Hairdryer used to trick weather sensor' to win Polymarket bet
by zdw on 4/23/2026, 5:01:01 PM
Comments
by: dzdt
This is small potatoes compared to the rain gauge tampering farmers were doing in Colorado. There was a recent conviction for $6.5 million dollars of fraud against the federal crop insurance program!<p><a href="https://www.justice.gov/usao-co/pr/two-southeastern-colorado-farmers-sentenced-federal-prison-and-will-pay-over-65-million" rel="nofollow">https://www.justice.gov/usao-co/pr/two-southeastern-colorado...</a>
4/23/2026, 6:11:34 PM
by: ambicapter
> There are no indications so far that the successful punters have had to return their winnings. However, the data source for Paris’s hottest temperature has since moved to a sensor at the smaller Paris-Le Bourget airport.<p>Here's the negative externality that no one will care about. There's no reason gamblers won't repeat this stunt, until us poor schmucks who just want an accurate temperature reading have to build a fortified compound in order to do so.
4/23/2026, 5:24:24 PM
by: strogonoff
Betting against what is widely considered as “expected”, “reasonable” is such a major source of profit when one can influence the income. Whether it’s a temperature sensor one can breathe on or movement of troops one can control or influence[0], the idea is the same—except in one of the above you can add “death and suffering” in addition to some unfortunate gamblers losing their money.<p>A depressing thought: it will only tip in favor of common good when the probability of something that we today consider “normal” becomes <i>so small</i> that betting on that finally becomes profitable to insiders with influence. Imagine that world…<p>[0] No, I’m not going to change my writing style because it is considered a “tell” of LLM use.
4/23/2026, 5:49:07 PM
by: guyzero
I don't understand who is taking the other side of all these insane Polymarket bets. Is Polymarket doing it?
4/23/2026, 5:16:17 PM
by: happyopossum
> While it is unclear how the temperature might have been manipulated, one possibility shared on weather forums was that a battery-powered hairdryer could have been used<p>Man I hate headline writers…<p>We’re I contracted to (legally and ethically) red team a temperature station, a “battery powered hair dryer” would be pretty low on my list of techniques for a number of reasons. First attempts would involve mirrors - parabolic or otherwise- to heat the device from a distance without potentially affecting wind speed / direction sensors.
4/23/2026, 5:45:58 PM
by: dlenski
> On April 15, one trader made $21,000 (£15,600) betting that the maximum temperature would not be 18 degrees, data from Polymarket show. A temperature of 18C was seen as a 99.6pc probability before the temperature spiked later in the day.<p>I believe that these are the specific Polymarket bets in question:<p>April 6 (<a href="https://polymarket.com/event/highest-temperature-in-paris-on-april-6-2026" rel="nofollow">https://polymarket.com/event/highest-temperature-in-paris-on...</a>): this appears to have been something of a "test run", since the odds weren't particularly lopsided until it suddenly spiked in the evening local time.<p>April 15 (<a href="https://polymarket.com/event/highest-temperature-in-paris-on-april-15-2026" rel="nofollow">https://polymarket.com/event/highest-temperature-in-paris-on...</a>): the odds were quite lopsided in favor of 18°C, until suddenly reversing in the evening. This is presumably where the fraudsters made all their money.
4/23/2026, 5:28:33 PM
by: dlev_pika
Is it clear already how bad of an idea, and social disservice, Polymarket/Kalshi are?
4/23/2026, 6:32:14 PM
by: ikeboy
Reminds me of when I made about $40k finding a source that had CO2 data in close to real time when other people were tracking one about 12 hours delayed<p>See <a href="https://misinfounderload.substack.com/p/tales-from-prediction-markets" rel="nofollow">https://misinfounderload.substack.com/p/tales-from-predictio...</a>
4/23/2026, 5:30:55 PM
by: ctime
Between this and crypto cryptocurrencies (which obviously can be used to make bets) I don’t know which is more destructive to society
4/23/2026, 5:23:34 PM
by: nanna
Why is Polymarket legal? I just don't understand.
4/23/2026, 5:38:53 PM
by: johnhamlin
Remember when it was just common sense that letting people gamble on things would undermine the integrity of those things?
4/23/2026, 6:25:31 PM
by: gmd63
Wonder how the founders/board/investors of the bad incentives factory would manage their site after a massive crowdfunding campaign bet that they'd all still be alive in 2027.
4/23/2026, 6:33:07 PM
by: iambateman
At some point, the market for markets will demand better regulation than this. But I find it a little absurd that anyone is still putting their money into these markets with story after story of obvious fraud.
4/23/2026, 6:29:13 PM
by: _trampeltier
Cheating with weather sensor is not new.<p>Wrecked rain gauges. Whistleblowers. Million-dollar payouts and manhunts.<p><a href="https://news.ycombinator.com/item?id=41485560">https://news.ycombinator.com/item?id=41485560</a>
4/23/2026, 6:28:23 PM
by: mkhpalm
Hair dryer? Or something like a mirror from a comfortable distance?
4/23/2026, 6:42:15 PM
by: waltbosz
If you have 3 minutes, here's an apropos BBC audio comedy sketch.<p><a href="https://youtu.be/ub01udUz7ns?si=OBMKdK6RED3aZMEq&t=15" rel="nofollow">https://youtu.be/ub01udUz7ns?si=OBMKdK6RED3aZMEq&t=15</a>
4/23/2026, 6:04:01 PM
by: dwa3592
Idea : "Manipulation of real world events because correct prediction of real world events is incentivized."<p>Try to scale this anywhere from hairdryer usage to trip temp sensors to nuclear bombs going off in poor countries.
4/23/2026, 5:47:01 PM
by: sebastianconcpt
Reminds me of not long ago someone writing about "Everything is Lies Now"
4/23/2026, 6:23:05 PM
by: w-m
John Oliver had a segment on prediction markets this week. It covers insider training and opportunities for blatant manipulation like this, well worth checking out. The example in the Last Week Tonight segment was betting on dildos being thrown on court during a WNBA match. And then travelling to the match to throw the dildo.<p>[0] <a href="https://www.youtube.com/watch?v=ZN4njIQcSR4" rel="nofollow">https://www.youtube.com/watch?v=ZN4njIQcSR4</a>
4/23/2026, 5:21:57 PM
by: jbrowning
> While it is unclear how the temperature might have been manipulated, one possibility shared on weather forums was that a battery-powered hairdryer could have been used, according to Le Monde newspaper.<p>Clickbait headline FWIW.
4/23/2026, 5:25:37 PM
by: efitz
The guy will be solely responsible for half a degree of global warming next year.
4/23/2026, 5:51:37 PM
by: mndgs
Beautiful con, tbh. I don't welcome this behavior (borderline criminal), but you have to admit - well played.
4/23/2026, 5:21:28 PM
by: vibe42
Outside Trading.
4/23/2026, 6:37:16 PM
by: jerf
The libertarian argument for prediction markets is really beautiful.<p>It's just a pity it basically depends on all participants in the prediction market being basically unaware that they are participating in a prediction market, and being oblivious to the incentives to create the outcomes they are predicting by the very act of predicting it with money.<p>But other than that minor detail, that little minor catastrophic flaw in the foundation, it's a beautiful argument.<p>I think we can call it as a society. It's a failure. We can go back to banning them, not just for moral reasons, but just pragmatic ones. The theory doesn't work. The supposed benefits don't manifest, and "unanticipated" costs to everyone do. We did the experiment. (Again.) We can close this out now.
4/23/2026, 6:09:21 PM
by: phendrenad2
Fun fact: Kalshi runs ads that start with a guy saying "I just made money because it snowed!"<p>Make of that what you will.
4/23/2026, 6:01:19 PM
by: ChrisArchitect
[dupe] <a href="https://news.ycombinator.com/item?id=47869664">https://news.ycombinator.com/item?id=47869664</a>
4/23/2026, 5:29:39 PM
by: krunck
Quite literally EVERYTHING around us is now subject to possible manipulation by these idiots if they think they can profit.<p>Even the US Government has executive and legislative officials profiting from secret information they know from doing their duties.<p>I wonder when someone who does cloud seeding will place a bet about rain at some unlikely time and place.<p>Or the next large forest fire.
4/23/2026, 6:05:20 PM
by: FrustratedMonky
Now bet that climate denials will use this as example that lots of temperature data is faked.
4/23/2026, 6:10:44 PM