Highest temperature in Paris on August 15?

Platform comparison

Market context

The market prices a 1% probability that Paris-Le Bourget Airport will record a temperature of 40°C or higher on 15 August 2026. August is Paris's warmest month, with historical daily maxima typically ranging from 24–26°C, though the city has experienced extreme heat events in recent decades. The 2003 European heat wave saw Paris reach 40.3°C on 4 August, whilst more recent summers have produced occasional days exceeding 35°C. The consensus implied by the 1% odds reflects the rarity of such extremes, positioning any temperature at or above 40°C as a genuine outlier rather than a routine summer occurrence.

The crowd's confidence in a sub-40°C outcome rests on long-term climate normals and the specificity of the date. Mid-August typically sits slightly cooler than early August in Paris, as seasonal patterns begin their gradual shift toward autumn. However, the resolution mechanism—drawing from Weather Underground's Daily Observations table at Le Bourget rather than summary figures—introduces a technical precision that could matter if readings hover near threshold boundaries. Traders should monitor European weather forecasting models as August 2026 approaches; any signals of an exceptional heat dome tracking northwestward into France during that window would materially shift the calculus. The market's current pricing leaves substantial room for upside if climate anomalies or atmospheric blocking patterns develop, though the historical baseline suggests the underdog position remains appropriately priced.

Methodology

This page reviews Highest temperature in Paris on August 15? across five venues. The live probability is the Polymarket mid-price, sourced directly from the on-chain Polygon order book; the comparison columns benchmark each venue on fee structure, KYC, settlement currency and payment rails. Every CTA routes to Who Will Win, which mirrors the Polymarket order book at 0% fees.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

UK Frequently Asked Questions

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 Who Will Win. 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.

Is Polymarket legal in the UK?

Polymarket is accessible to UK traders but is not UKGC-licensed. It operates under US CFTC jurisdiction. UK residents face no domestic legal prohibition on using it, but UKGC consumer protections do not apply. For UKGC-regulated alternatives, Betfair Exchange and Smarkets offer similar prediction-style markets.

Do I pay tax on prediction market profits in the UK?

UKGC-licensed platform profits (Betfair, Smarkets) are typically tax-free gambling winnings for UK individuals. Polymarket profits involve USDC crypto transactions, which HMRC treats as Capital Gains Tax events. Keep full transaction records and report via Self Assessment if gains exceed £3,000 per tax year.

How do I deposit on Polymarket from the UK?

UK traders typically fund Polymarket via Coinbase UK, Kraken or Revolut — buying USDC with GBP and transferring to a Polygon-compatible wallet (MetaMask, Coinbase Wallet). Polymarket's onboarding walks you through the bridging process. Typical GBP-to-USDC conversion costs 0.5–1%.