Highest temperature in Paris on August 15?

Platform comparison

Market context

Paris-Le Bourget Airport will record a daily maximum temperature on 15 August 2026. The resolution hinges on the specific data point captured in Weather Underground's Daily Observations table—the granular, station-level record rather than the rounded summary figures—which introduces a technical dependency worth noting for programmatic monitoring. A 1% crowd probability suggests the market is pricing in either a notably cool August day or uncertainty about what threshold constitutes the resolution range itself.

Historical August temperatures at Le Bourget show a median high around 25–26°C, with extremes reaching 38°C (2003) and dipping to 17°C in cooler years. The 2003 European heat wave remains the reference case for extreme upside; recent summers (2022–2024) have produced several days above 30°C in mid-August. This distribution means the crowd's 1% reading likely reflects scepticism about an unusually high or unusually low outcome, depending on the specific temperature band the market is testing.

Traders building automated monitoring should flag two dependencies: Weather Underground's data pipeline integrity (occasional station outages or corrections occur post-settlement) and the distinction between Le Bourget's official readings and other Paris-area stations, which can vary by 2–3°C. Seasonal forecasts from Météo-France and European medium-range models (ECMWF) become actionable from mid-July onward. The settlement window closes at noon UTC on the day itself, creating a narrow window for final position adjustments once morning observations confirm the trajectory.

Methodology

We track Highest temperature in Paris on August 15? across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is Kalshi Fees. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.